diff --git a/sao/src/sao.less b/sao/src/sao.less
index 68935a6128..bac1b8d556 100644
--- a/sao/src/sao.less
+++ b/sao/src/sao.less
@@ -637,8 +637,8 @@ img.icon {
     }
     .form-text, .form-richtext {
         > textarea, .richtext {
+            height: 100%;
             line-height: 2.5ex;
-            max-height: 50ex;
             min-height: 12.5ex;
             overflow: auto;
             resize: vertical;