diff --git a/blockchain/blockchain_test.go b/blockchain/blockchain_test.go
new file mode 100644
index 000000000..08e7ef077
--- /dev/null
+++ b/blockchain/blockchain_test.go
@@ -0,0 +1,39 @@
+package blockchain
+
+import (
+	"testing"
+)
+
+func TestCreateBlockchain(t *testing.T) {
+	CreateBlockchain("minh")
+}
+
+func TestFindSpendableOutputs(t *testing.T) {
+	requestAmount := 3
+	bc := CreateBlockchain("minh")
+	accumulated, unspentOutputs := bc.FindSpendableOutputs("minh", requestAmount)
+	if accumulated < DefaultCoinbaseValue {
+		t.Error("Failed to find enough unspent ouptuts")
+	}
+
+	if len(unspentOutputs) <= 0 {
+		t.Error("Failed to find enough unspent ouptuts")
+	}
+}
+
+func TestFindUTXO(t *testing.T) {
+	bc := CreateBlockchain("minh")
+	utxo := bc.FindUTXO("minh")
+
+	total := 0
+	for _, value := range utxo {
+		total += value.Value
+		if value.Address != "minh" {
+			t.Error("FindUTXO failed.")
+		}
+	}
+
+	if total != DefaultCoinbaseValue {
+		t.Error("FindUTXO failed.")
+	}
+}
diff --git a/blockchain/transaction.go b/blockchain/transaction.go
index 303aa28aa..d8bce39e4 100644
--- a/blockchain/transaction.go
+++ b/blockchain/transaction.go
@@ -30,7 +30,7 @@ type TXInput struct {
 }
 
 // DefaultCoinbaseValue is the default value of coinbase transaction.
-const DefaultCoinbaseValue = 10
+const DefaultCoinbaseValue = 1000
 
 // SetID sets ID of a transaction
 func (tx *Transaction) SetID() {