diff --git a/common/yerror/basic_error.go b/common/yerror/basic_error.go
index fb7b217..76c0972 100644
--- a/common/yerror/basic_error.go
+++ b/common/yerror/basic_error.go
@@ -20,10 +20,11 @@ var NoKvdbType = errors.New("no kvdb type")
 var NoSqlDbType = errors.New("no sqlDB type")
 
 var (
-	PoolOverflow  error = errors.New("pool size is full")
-	TxnTimeoutErr error = errors.New("Txn time out")
-	TxnTooLarge   error = errors.New("the size of txn is too large")
-	TxnDuplicated error = errors.New("Transaction duplicated")
+	PoolOverflow   error = errors.New("pool size is full")
+	TxnTimeoutErr  error = errors.New("Txn time out")
+	TxnTooLarge    error = errors.New("the size of txn is too large")
+	TxnDuplicated  error = errors.New("Transaction duplicated")
+	ChainIDIllegal error = errors.New("chain id illegal")
 )
 
 var ErrBlockNotFound error = errors.New("block not found")
diff --git a/core/kernel/handle_input.go b/core/kernel/handle_input.go
index c487382..3cd08b4 100644
--- a/core/kernel/handle_input.go
+++ b/core/kernel/handle_input.go
@@ -70,10 +70,11 @@ func (k *Kernel) handleTxnLocally(stxn *SignedTxn, topic string) error {
 			return err
 		}
 	}
-	if k.CheckReplayAttack(stxn) {
-		return yerror.TxnDuplicated
+	err := k.CheckReplayAttack(stxn)
+	if err != nil {
+		return err
 	}
-	err := k.Pool.CheckTxn(stxn)
+	err = k.Pool.CheckTxn(stxn)
 	if err != nil {
 		return err
 	}
@@ -97,14 +98,18 @@ func (k *Kernel) HandleReading(rdCall *common.RdCall) (*context.ResponseData, er
 	return ctx.Response(), nil
 }
 
-func (k *Kernel) CheckReplayAttack(txn *SignedTxn) bool {
+func (k *Kernel) CheckReplayAttack(txn *SignedTxn) error {
+	if k.Chain.ChainID() != txn.ChainID() {
+		return yerror.ChainIDIllegal
+	}
 	if k.Pool.Exist(txn.TxnHash) {
-		return true
+		return yerror.TxnDuplicated
 	}
-	if k.Chain.ChainID() != txn.ChainID() {
-		return true
+
+	if k.TxDB.ExistTxn(txn.TxnHash) {
+		return yerror.TxnDuplicated
 	}
-	return k.TxDB.ExistTxn(txn.TxnHash)
+	return nil
 }
 
 //func getRdFromHttp(req *http.Request, params string) (rdCall *RdCall, err error) {
diff --git a/core/kernel/kernel.go b/core/kernel/kernel.go
index 8d216b7..2fab2c5 100644
--- a/core/kernel/kernel.go
+++ b/core/kernel/kernel.go
@@ -101,7 +101,7 @@ func (k *Kernel) AcceptUnpackedTxns() error {
 	}
 
 	for _, txn := range writings {
-		if k.CheckReplayAttack(txn) {
+		if err := k.CheckReplayAttack(txn); err != nil {
 			continue
 		}
 		txn.FromP2P = true
@@ -130,7 +130,7 @@ func (k *Kernel) AcceptUnpackedTxns() error {
 			if txn == nil {
 				continue
 			}
-			if k.CheckReplayAttack(txn) {
+			if err := k.CheckReplayAttack(txn); err != nil {
 				continue
 			}
 			txn.FromP2P = true