diff --git a/components/net/lwip/src/arch/sys_arch.c b/components/net/lwip/src/arch/sys_arch.c
index 2f1135294d67b4921787a9fc9e41ed14e035c490..98fe8588e1fd2c152a72ea8ced4c427cc63216f0 100644
--- a/components/net/lwip/src/arch/sys_arch.c
+++ b/components/net/lwip/src/arch/sys_arch.c
@@ -534,7 +534,7 @@ u32_t sys_jiffies(void)
 
 u32_t sio_read(sio_fd_t fd, u8_t *buf, u32_t size)
 {
-    u32_t len, i;
+    u32_t len;
 
     RT_ASSERT(fd != RT_NULL);
 
@@ -547,7 +547,6 @@ u32_t sio_read(sio_fd_t fd, u8_t *buf, u32_t size)
 
 u32_t sio_write(sio_fd_t fd, u8_t *buf, u32_t size)
 {
-    u32_t i;
     RT_ASSERT(fd != RT_NULL);
 
     return rt_device_write((rt_device_t)fd, 0, buf, size);