diff --git a/Segment_Tree/370.Range-Addition/370.Range-Addition_SegTree.cpp b/Segment_Tree/370.Range-Addition/370.Range-Addition_SegTree.cpp
index 14e9e8d19..aedfcc976 100644
--- a/Segment_Tree/370.Range-Addition/370.Range-Addition_SegTree.cpp
+++ b/Segment_Tree/370.Range-Addition/370.Range-Addition_SegTree.cpp
@@ -41,7 +41,7 @@ class SegTreeNode
         }        
     } 
     
-    void updateRangeBy(int a, int b, int val)     // set range [a,b] with val
+    void updateRangeBy(int a, int b, int val)     // increase range [a,b] by val
     {        
         if (b < start || a > end ) // not covered by [a,b] at all
             return;