diff --git a/README.md b/README.md
index 34e279f..0891fb5 100644
--- a/README.md
+++ b/README.md
@@ -64,10 +64,12 @@ Cmake option:
 
 `CONFIG`: Set Target Platform. Such as: `A311D`, `S905D3`, `vim3_android`, `YOCTO`. Default is `X86_64_linux`.
 
-`TIM_VX_ENABLE_TEST`: Build the unit test. Default is ON.
+`TIM_VX_ENABLE_TEST`: Build the unit test. Default is OFF.
 
 `TIM_VX_USE_EXTERNAL_OVXLIB`: Use external OVXLIB. Default is OFF.
 
+`EXTERNAL_VIV_SDK`: use external VX driver libs. By default is OFF.
+
 run unit test:
 
 ```shell