diff --git a/core/chain_makers.go b/core/chain_makers.go
index 8a071a6e2..4c8b4b920 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -71,9 +71,9 @@ func (b *BlockGen) SetNonce(nonce types.BlockNonce) {
 	b.header.Nonce = nonce
 }
 
-// SetShardID sets the shardId field of the generated block.
-func (b *BlockGen) SetShardID(shardId types.ShardID) {
-	b.header.ShardID = shardId
+// SetShardID sets the shardID field of the generated block.
+func (b *BlockGen) SetShardID(shardID types.ShardID) {
+	b.header.ShardID = shardID
 }
 
 // AddTx adds a transaction to the generated block. If no coinbase has
diff --git a/core/genesis.go b/core/genesis.go
index 52c15e04c..994de6548 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -45,7 +45,7 @@ var errGenesisNoConfig = errors.New("genesis has no chain configuration")
 type Genesis struct {
 	Config     *params.ChainConfig `json:"config"`
 	Nonce      uint64              `json:"nonce"`
-	ShardID    uint32              `json:"shardId"`
+	ShardID    uint32              `json:"shardID"`
 	Timestamp  uint64              `json:"timestamp"`
 	ExtraData  []byte              `json:"extraData"`
 	GasLimit   uint64              `json:"gasLimit"   gencodec:"required"`
diff --git a/core/types/block.go b/core/types/block.go
index 945da2122..cfb46ed2b 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -75,8 +75,6 @@ func (n *BlockNonce) UnmarshalText(input []byte) error {
 	return hexutil.UnmarshalFixedText("BlockNonce", input, n[:])
 }
 
-//go:generate gencodec -type Header -field-override headerMarshaling -out gen_header_json.go
-
 // Header represents a block header in the Ethereum blockchain.
 type Header struct {
 	ParentHash  common.Hash    `json:"parentHash"       gencodec:"required"`
@@ -93,7 +91,7 @@ type Header struct {
 	Extra       []byte         `json:"extraData"        gencodec:"required"`
 	MixDigest   common.Hash    `json:"mixHash"          gencodec:"required"`
 	Nonce       BlockNonce     `json:"nonce"            gencodec:"required"`
-	ShardID     ShardID        `json:"shardId"          gencodec:"required"`
+	ShardID     ShardID        `json:"shardID"          gencodec:"required"`
 }
 
 // field type overrides for gencodec
@@ -302,7 +300,7 @@ func (b *Block) GasUsed() uint64 { return b.header.GasUsed }
 // Difficulty is the header difficulty.
 func (b *Block) Difficulty() *big.Int { return new(big.Int).Set(b.header.Difficulty) }
 
-// TIme is header time.
+// Time is header time.
 func (b *Block) Time() *big.Int { return new(big.Int).Set(b.header.Time) }
 
 // NumberU64 is the header number in uint64.
@@ -315,15 +313,30 @@ func (b *Block) MixDigest() common.Hash { return b.header.MixDigest }
 func (b *Block) Nonce() uint64 { return binary.BigEndian.Uint64(b.header.Nonce[:]) }
 
 // ShardID is the header ShardID
-func (b *Block) ShardID() uint32          { return binary.BigEndian.Uint32(b.header.ShardID[:]) }
-func (b *Block) Bloom() Bloom             { return b.header.Bloom }
+func (b *Block) ShardID() uint32 { return binary.BigEndian.Uint32(b.header.ShardID[:]) }
+
+// Bloom returns header bloom.
+func (b *Block) Bloom() Bloom { return b.header.Bloom }
+
+// Coinbase returns header coinbase.
 func (b *Block) Coinbase() common.Address { return b.header.Coinbase }
-func (b *Block) Root() common.Hash        { return b.header.Root }
-func (b *Block) ParentHash() common.Hash  { return b.header.ParentHash }
-func (b *Block) TxHash() common.Hash      { return b.header.TxHash }
+
+// Root returns header root.
+func (b *Block) Root() common.Hash { return b.header.Root }
+
+// ParentHash return header parent hash.
+func (b *Block) ParentHash() common.Hash { return b.header.ParentHash }
+
+// TxHash returns header tx hash.
+func (b *Block) TxHash() common.Hash { return b.header.TxHash }
+
+// ReceiptHash returns header receipt hash.
 func (b *Block) ReceiptHash() common.Hash { return b.header.ReceiptHash }
-func (b *Block) Extra() []byte            { return common.CopyBytes(b.header.Extra) }
 
+// Extra returns header extra.
+func (b *Block) Extra() []byte { return common.CopyBytes(b.header.Extra) }
+
+// Header returns a copy of Header.
 func (b *Block) Header() *Header { return CopyHeader(b.header) }
 
 // Body returns the non-header content of the block.
@@ -348,6 +361,7 @@ func (c *writeCounter) Write(b []byte) (int, error) {
 	return len(b), nil
 }
 
+// CalcUncleHash returns rlp hash of uncles.
 func CalcUncleHash(uncles []*Header) common.Hash {
 	return rlpHash(uncles)
 }
@@ -410,15 +424,21 @@ type blockSorter struct {
 }
 
 // Len returns len of the blocks.
-func (self blockSorter) Len() int { return len(self.blocks) }
+func (s blockSorter) Len() int {
+	return len(s.blocks)
+}
 
 // Swap swaps block i and block j.
-func (self blockSorter) Swap(i, j int) {
-	self.blocks[i], self.blocks[j] = self.blocks[j], self.blocks[i]
+func (s blockSorter) Swap(i, j int) {
+	s.blocks[i], s.blocks[j] = s.blocks[j], s.blocks[i]
 }
 
 // Less checks if block i is less than block j.
-func (self blockSorter) Less(i, j int) bool { return self.by(self.blocks[i], self.blocks[j]) }
+func (s blockSorter) Less(i, j int) bool {
+	return s.by(s.blocks[i], s.blocks[j])
+}
 
 // Number checks if block b1 is less than block b2.
-func Number(b1, b2 *Block) bool { return b1.header.Number.Cmp(b2.header.Number) < 0 }
+func Number(b1, b2 *Block) bool {
+	return b1.header.Number.Cmp(b2.header.Number) < 0
+}
diff --git a/core/types/bloom9.go b/core/types/bloom9.go
index d045c9e66..5b4ca44b1 100644
--- a/core/types/bloom9.go
+++ b/core/types/bloom9.go
@@ -68,14 +68,17 @@ func (b Bloom) Big() *big.Int {
 	return new(big.Int).SetBytes(b[:])
 }
 
+// Bytes returns bytes of Bloom.
 func (b Bloom) Bytes() []byte {
 	return b[:]
 }
 
+// Test tests if an input may belong to the bloom.
 func (b Bloom) Test(test *big.Int) bool {
 	return BloomLookup(b, test)
 }
 
+// TestBytes tests if the input represented by test []byte may belong to the bloom.
 func (b Bloom) TestBytes(test []byte) bool {
 	return b.Test(new(big.Int).SetBytes(test))
 
@@ -91,6 +94,7 @@ func (b *Bloom) UnmarshalText(input []byte) error {
 	return hexutil.UnmarshalFixedText("Bloom", input, b[:])
 }
 
+// CreateBloom creates a Bloom given the receipts.
 func CreateBloom(receipts Receipts) Bloom {
 	bin := new(big.Int)
 	for _, receipt := range receipts {
@@ -100,6 +104,7 @@ func CreateBloom(receipts Receipts) Bloom {
 	return BytesToBloom(bin.Bytes())
 }
 
+// LogsBloom ...
 func LogsBloom(logs []*Log) *big.Int {
 	bin := new(big.Int)
 	for _, log := range logs {
@@ -126,8 +131,10 @@ func bloom9(b []byte) *big.Int {
 	return r
 }
 
+// Bloom9 type.
 var Bloom9 = bloom9
 
+// BloomLookup checks if a topic may belong to the Bloom.
 func BloomLookup(bin Bloom, topic bytesBacked) bool {
 	bloom := bin.Big()
 	cmp := bloom9(topic.Bytes())
diff --git a/core/types/derive_sha.go b/core/types/derive_sha.go
index 00c42c5bc..d7eaf160b 100644
--- a/core/types/derive_sha.go
+++ b/core/types/derive_sha.go
@@ -24,11 +24,13 @@ import (
 	"github.com/ethereum/go-ethereum/trie"
 )
 
+// DerivableList is the interface of DerivableList.
 type DerivableList interface {
 	Len() int
 	GetRlp(i int) []byte
 }
 
+// DeriveSha calculates the hash of the trie generated by DerivableList.
 func DeriveSha(list DerivableList) common.Hash {
 	keybuf := new(bytes.Buffer)
 	trie := new(trie.Trie)
diff --git a/core/types/transaction.go b/core/types/transaction.go
index 035839be1..eb9da3942 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -31,10 +31,12 @@ import (
 
 //go:generate gencodec -type txdata -field-override txdataMarshaling -out gen_tx_json.go
 
+// Errors constants for Transaction.
 var (
 	ErrInvalidSig = errors.New("invalid transaction v, r, s values")
 )
 
+// Transaction struct.
 type Transaction struct {
 	data txdata
 	// caches
@@ -45,7 +47,7 @@ type Transaction struct {
 
 type txdata struct {
 	AccountNonce uint64          `json:"nonce"    gencodec:"required"`
-	ShardID      uint32          `json:"shardId"  gencodec:"required"`
+	ShardID      uint32          `json:"shardID"  gencodec:"required"`
 	Price        *big.Int        `json:"gasPrice" gencodec:"required"`
 	GasLimit     uint64          `json:"gas"      gencodec:"required"`
 	Recipient    *common.Address `json:"to"       rlp:"nil"` // nil means contract creation
@@ -72,22 +74,24 @@ type txdataMarshaling struct {
 	S            *hexutil.Big
 }
 
-func NewTransaction(nonce uint64, to common.Address, shardId uint32, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
-	return newTransaction(nonce, &to, shardId, amount, gasLimit, gasPrice, data)
+// NewTransaction returns new transaction.
+func NewTransaction(nonce uint64, to common.Address, shardID uint32, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
+	return newTransaction(nonce, &to, shardID, amount, gasLimit, gasPrice, data)
 }
 
-func NewContractCreation(nonce uint64, shardId uint32, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
-	return newTransaction(nonce, nil, shardId, amount, gasLimit, gasPrice, data)
+// NewContractCreation returns contract transaction.
+func NewContractCreation(nonce uint64, shardID uint32, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
+	return newTransaction(nonce, nil, shardID, amount, gasLimit, gasPrice, data)
 }
 
-func newTransaction(nonce uint64, to *common.Address, shardId uint32, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
+func newTransaction(nonce uint64, to *common.Address, shardID uint32, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
 	if len(data) > 0 {
 		data = common.CopyBytes(data)
 	}
 	d := txdata{
 		AccountNonce: nonce,
 		Recipient:    to,
-		ShardID:      shardId,
+		ShardID:      shardID,
 		Payload:      data,
 		Amount:       new(big.Int),
 		GasLimit:     gasLimit,
@@ -106,9 +110,9 @@ func newTransaction(nonce uint64, to *common.Address, shardId uint32, amount *bi
 	return &Transaction{data: d}
 }
 
-// ChainId returns which chain id this transaction was signed for (if at all)
-func (tx *Transaction) ChainId() *big.Int {
-	return deriveChainId(tx.data.V)
+// ChainID returns which chain id this transaction was signed for (if at all)
+func (tx *Transaction) ChainID() *big.Int {
+	return deriveChainID(tx.data.V)
 }
 
 // Protected returns whether the transaction is protected from replay protection.
@@ -160,7 +164,7 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 	if withSignature {
 		var V byte
 		if isProtectedV(dec.V) {
-			chainID := deriveChainId(dec.V).Uint64()
+			chainID := deriveChainID(dec.V).Uint64()
 			V = byte(dec.V.Uint64() - 35 - 2*chainID)
 		} else {
 			V = byte(dec.V.Uint64() - 27)
@@ -174,12 +178,35 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 	return nil
 }
 
-func (tx *Transaction) Data() []byte       { return common.CopyBytes(tx.data.Payload) }
-func (tx *Transaction) Gas() uint64        { return tx.data.GasLimit }
-func (tx *Transaction) GasPrice() *big.Int { return new(big.Int).Set(tx.data.Price) }
-func (tx *Transaction) Value() *big.Int    { return new(big.Int).Set(tx.data.Amount) }
-func (tx *Transaction) Nonce() uint64      { return tx.data.AccountNonce }
-func (tx *Transaction) CheckNonce() bool   { return true }
+// Data returns data payload of Transaction.
+func (tx *Transaction) Data() []byte {
+	return common.CopyBytes(tx.data.Payload)
+}
+
+// Gas returns gas of Transaction.
+func (tx *Transaction) Gas() uint64 {
+	return tx.data.GasLimit
+}
+
+// GasPrice returns gas price of Transaction.
+func (tx *Transaction) GasPrice() *big.Int {
+	return new(big.Int).Set(tx.data.Price)
+}
+
+// Value returns data payload of Transaction.
+func (tx *Transaction) Value() *big.Int {
+	return new(big.Int).Set(tx.data.Amount)
+}
+
+// Nonce returns account nonce from Transaction.
+func (tx *Transaction) Nonce() uint64 {
+	return tx.data.AccountNonce
+}
+
+// CheckNonce returns check nonce from Transaction.
+func (tx *Transaction) CheckNonce() bool {
+	return true
+}
 
 // To returns the recipient address of the transaction.
 // It returns nil if the transaction is a contract creation.
@@ -409,11 +436,42 @@ func NewMessage(from common.Address, to *common.Address, nonce uint64, amount *b
 	}
 }
 
-func (m Message) From() common.Address { return m.from }
-func (m Message) To() *common.Address  { return m.to }
-func (m Message) GasPrice() *big.Int   { return m.gasPrice }
-func (m Message) Value() *big.Int      { return m.amount }
-func (m Message) Gas() uint64          { return m.gasLimit }
-func (m Message) Nonce() uint64        { return m.nonce }
-func (m Message) Data() []byte         { return m.data }
-func (m Message) CheckNonce() bool     { return m.checkNonce }
+// From returns from address from Message.
+func (m Message) From() common.Address {
+	return m.from
+}
+
+// To returns to address from Message.
+func (m Message) To() *common.Address {
+	return m.to
+}
+
+// GasPrice returns gas price from Message.
+func (m Message) GasPrice() *big.Int {
+	return m.gasPrice
+}
+
+// Value returns the value amount from Message.
+func (m Message) Value() *big.Int {
+	return m.amount
+}
+
+// Gas returns gas limit of the Message.
+func (m Message) Gas() uint64 {
+	return m.gasLimit
+}
+
+// Nonce returns Nonce of the Message.
+func (m Message) Nonce() uint64 {
+	return m.nonce
+}
+
+// Data return data of the Message.
+func (m Message) Data() []byte {
+	return m.data
+}
+
+// CheckNonce returns checkNonce of Message.
+func (m Message) CheckNonce() bool {
+	return m.checkNonce
+}
diff --git a/core/types/transaction_signing.go b/core/types/transaction_signing.go
index 81abef1cf..290a12887 100644
--- a/core/types/transaction_signing.go
+++ b/core/types/transaction_signing.go
@@ -29,7 +29,7 @@ import (
 
 // Constants for transaction signing.
 var (
-	ErrInvalidChainId = errors.New("invalid chain id for signer")
+	ErrInvalidChainID = errors.New("invalid chain id for signer")
 )
 
 // sigCache is used to cache the derived sender and contains
@@ -129,8 +129,8 @@ func (s EIP155Signer) Sender(tx *Transaction) (common.Address, error) {
 	if !tx.Protected() {
 		return HomesteadSigner{}.Sender(tx)
 	}
-	if tx.ChainId().Cmp(s.chainId) != 0 {
-		return common.Address{}, ErrInvalidChainId
+	if tx.ChainID().Cmp(s.chainId) != 0 {
+		return common.Address{}, ErrInvalidChainID
 	}
 	V := new(big.Int).Sub(tx.data.V, s.chainIdMul)
 	V.Sub(V, big8)
@@ -247,8 +247,8 @@ func recoverPlain(sighash common.Hash, R, S, Vb *big.Int, homestead bool) (commo
 	return addr, nil
 }
 
-// deriveChainId derives the chain id from the given v parameter
-func deriveChainId(v *big.Int) *big.Int {
+// deriveChainID derives the chain id from the given v parameter
+func deriveChainID(v *big.Int) *big.Int {
 	if v.BitLen() <= 64 {
 		v := v.Uint64()
 		if v == 27 || v == 28 {
diff --git a/core/types/transaction_signing_test.go b/core/types/transaction_signing_test.go
index 70f69dabc..e6ea1f9e7 100644
--- a/core/types/transaction_signing_test.go
+++ b/core/types/transaction_signing_test.go
@@ -43,7 +43,7 @@ func TestEIP155Signing(t *testing.T) {
 	}
 }
 
-func TestEIP155ChainId(t *testing.T) {
+func TestEIP155ChainID(t *testing.T) {
 	key, _ := crypto.GenerateKey()
 	addr := crypto.PubkeyToAddress(key.PublicKey)
 
@@ -56,8 +56,8 @@ func TestEIP155ChainId(t *testing.T) {
 		t.Fatal("expected tx to be protected")
 	}
 
-	if tx.ChainId().Cmp(signer.chainId) != 0 {
-		t.Error("expected chainId to be", signer.chainId, "got", tx.ChainId())
+	if tx.ChainID().Cmp(signer.chainId) != 0 {
+		t.Error("expected chainId to be", signer.chainId, "got", tx.ChainID())
 	}
 
 	tx = NewTransaction(0, addr, 0, new(big.Int), 0, new(big.Int), nil)
@@ -70,12 +70,12 @@ func TestEIP155ChainId(t *testing.T) {
 		t.Error("didn't expect tx to be protected")
 	}
 
-	if tx.ChainId().Sign() != 0 {
-		t.Error("expected chain id to be 0 got", tx.ChainId())
+	if tx.ChainID().Sign() != 0 {
+		t.Error("expected chain id to be 0 got", tx.ChainID())
 	}
 }
 
-func TestChainId(t *testing.T) {
+func TestChainID(t *testing.T) {
 	key, _ := defaultTestKey()
 
 	tx := NewTransaction(0, common.Address{}, 0, new(big.Int), 0, new(big.Int), nil)
@@ -87,8 +87,8 @@ func TestChainId(t *testing.T) {
 	}
 
 	_, err = Sender(NewEIP155Signer(big.NewInt(2)), tx)
-	if err != ErrInvalidChainId {
-		t.Error("expected error:", ErrInvalidChainId)
+	if err != ErrInvalidChainID {
+		t.Error("expected error:", ErrInvalidChainID)
 	}
 
 	_, err = Sender(NewEIP155Signer(big.NewInt(1)), tx)
diff --git a/core/types/transaction_test.go b/core/types/transaction_test.go
index 1c25f2a37..aeb8c77e8 100644
--- a/core/types/transaction_test.go
+++ b/core/types/transaction_test.go
@@ -172,8 +172,8 @@ func TestTransactionJSON(t *testing.T) {
 		if tx.Hash() != parsedTx.Hash() {
 			t.Errorf("parsed tx differs from original tx, want %v, got %v", tx, parsedTx)
 		}
-		if tx.ChainId().Cmp(parsedTx.ChainId()) != 0 {
-			t.Errorf("invalid chain id, want %d, got %d", tx.ChainId(), parsedTx.ChainId())
+		if tx.ChainID().Cmp(parsedTx.ChainID()) != 0 {
+			t.Errorf("invalid chain id, want %d, got %d", tx.ChainID(), parsedTx.ChainID())
 		}
 	}
 }
diff --git a/node/node.go b/node/node.go
index f8c58bef6..c6afbbcfe 100644
--- a/node/node.go
+++ b/node/node.go
@@ -297,7 +297,7 @@ func New(consensus *bft.Consensus, db *hdb.LDBDatabase, selfPeer p2p.Peer) *Node
 
 		database := hdb.NewMemDatabase()
 		chainConfig := params.TestChainConfig
-		chainConfig.ChainID = big.NewInt(int64(node.Consensus.ShardID)) // Use ChainId as piggybacked ShardID
+		chainConfig.ChainID = big.NewInt(int64(node.Consensus.ShardID)) // Use ChainID as piggybacked ShardID
 		gspec := core.Genesis{
 			Config:  chainConfig,
 			Alloc:   genesisAloc,