diff --git a/sm9/sm9.go b/sm9/sm9.go
index 200b29b..78b12aa 100644
--- a/sm9/sm9.go
+++ b/sm9/sm9.go
@@ -529,16 +529,17 @@ func DecryptASN1(priv *EncryptPrivateKey, uid, ciphertext []byte) ([]byte, error
 	return decrypt(c, key[:key1Len], key[key1Len:], c2Bytes, c3Bytes, opts)
 }
 
-// Decrypt decrypt chipher, ciphertext should be with ASN.1 format according
-// SM9 cryptographic algorithm application specification, SM9Cipher definition.
+// Decrypt decrypt chipher, ciphertext should be with format C1||C3||C2
 func (priv *EncryptPrivateKey) Decrypt(uid, ciphertext []byte, opts EncrypterOpts) ([]byte, error) {
-	if ciphertext[0] == 0x30 { // should be ASN.1 format
-		return DecryptASN1(priv, uid, ciphertext)
-	}
-	// fallback to C1||C3||C2 raw format
 	return Decrypt(priv, uid, ciphertext, opts)
 }
 
+// DecryptASN1 decrypt chipher, ciphertext should be with ASN.1 format according
+// SM9 cryptographic algorithm application specification, SM9Cipher definition.
+func (priv *EncryptPrivateKey) DecryptASN1(uid, ciphertext []byte) ([]byte, error) {
+	return DecryptASN1(priv, uid, ciphertext)
+}
+
 // KeyExchange key exchange struct, include internal stat in whole key exchange flow.
 // Initiator's flow will be: NewKeyExchange -> InitKeyExchange -> transmission -> ConfirmResponder
 // Responder's flow will be: NewKeyExchange -> waiting ... -> RepondKeyExchange -> transmission -> ConfirmInitiator
diff --git a/sm9/sm9_test.go b/sm9/sm9_test.go
index 23bb723..5ae86dd 100644
--- a/sm9/sm9_test.go
+++ b/sm9/sm9_test.go
@@ -750,7 +750,7 @@ func TestEncryptDecrypt(t *testing.T) {
 
 		got, err = userKey.Decrypt(uid, cipher, opts)
 		if err != nil {
-			t.Fatal(err)
+			t.Fatalf("encType %v, first byte %x, %v", opts.GetEncryptType(), cipher[0], err)
 		}
 
 		if string(got) != string(plaintext) {
@@ -789,7 +789,7 @@ func TestEncryptDecryptASN1(t *testing.T) {
 			t.Errorf("expected %v, got %v\n", string(plaintext), string(got))
 		}
 
-		got, err = userKey.Decrypt(uid, cipher, opts)
+		got, err = userKey.DecryptASN1(uid, cipher)
 		if err != nil {
 			t.Fatal(err)
 		}