diff --git a/problems/0209.长度最小的子数组.md b/problems/0209.长度最小的子数组.md
index fbef7692..160f93bb 100644
--- a/problems/0209.长度最小的子数组.md
+++ b/problems/0209.长度最小的子数组.md
@@ -162,8 +162,27 @@ class Solution:
                 index += 1
         return 0 if res==float("inf") else res
 ```
-
-
+```python3
+#滑动窗口
+class Solution:
+    def minSubArrayLen(self, target: int, nums: List[int]) -> int:
+        if nums is None or len(nums)==0: 
+            return 0 
+        lenf=len(nums)+1
+        total=0
+        i=j=0
+        while (j<len(nums)):
+            total=total+nums[j]
+            j+=1
+            while (total>=target):
+                lenf=min(lenf,j-i)
+                total=total-nums[i]
+                i+=1
+        if lenf==len(nums)+1:
+            return 0
+        else: 
+            return lenf
+```
 Go：
 ```go
 func minSubArrayLen(target int, nums []int) int {