diff --git a/README.md b/README.md
index 862d846..7cbc88c 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ This is a **SM2 sm2p256v1** implementation whose performance is similar like gol
 
 This is also a **SM3** implementation whose performance is similar like golang native SHA 256 under **amd64**, for implementation detail, please refer https://github.com/emmansun/gmsm/wiki/SM3%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96.
 
-For **SM4** implementation, AES-NI is used for under **amd64**.
+For **SM4** implementation, AES-NI is used under **amd64**.
 
 **SM2 encryption Benchmark**