diff --git a/packages/fineui/src/less/base/tree/ztree.less b/packages/fineui/src/less/base/tree/ztree.less
index e9eee2c97..e7869baae 100644
--- a/packages/fineui/src/less/base/tree/ztree.less
+++ b/packages/fineui/src/less/base/tree/ztree.less
@@ -272,7 +272,9 @@
 }
 
 .bi-theme-dark {
-  .ztree.solid li span.button.center_docu, .ztree.solid li span.button.bottom_docu {
+  .ztree.solid li span.button.center_docu, .ztree.solid li span.button.bottom_docu,.ztree.solid li span.button.roots_docu {
+    background: none;
+    
     &:before {
       border-right: 1px solid @border-color-dark-gray-line-theme-dark;
     }