diff --git a/problems/0501.二叉搜索树中的众数.md b/problems/0501.二叉搜索树中的众数.md
index 3ca7d892..1831a7a5 100644
--- a/problems/0501.二叉搜索树中的众数.md
+++ b/problems/0501.二叉搜索树中的众数.md
@@ -523,6 +523,55 @@ func traversal(root *TreeNode,result *[]int,pre *TreeNode){//遍历统计
 }
 ```
 
+JavaScript版本
+
+```javascript
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number[]}
+ */
+var findMode = function (root) {
+    let maxCount = 0;
+    let curCount = 0;
+    let pre = null;
+    let res = [];
+    const inOrder = (root) => {
+        if (root === null)
+            return;
+        inOrder(root.left);
+
+        if (pre === null)
+            curCount = 1;
+        else if (pre.val === root.val)
+            curCount++;
+        else
+            curCount = 1;
+        pre = root;
+
+        if (curCount === maxCount)
+            res.push(root.val);
+
+        if (curCount > maxCount) {
+            maxCount = curCount;
+            res.splice(0, res.length);
+            res.push(root.val);
+        }
+
+        inOrder(root.right);
+        return;
+    }
+    inOrder(root);
+    return res;
+};
+```
 
 
 -----------------------