diff --git "a/leetcode3/\354\265\234\353\257\274\354\247\200/1329.py" "b/leetcode3/\354\265\234\353\257\274\354\247\200/1329.py"
new file mode 100644
index 00000000..eaf5513e
--- /dev/null
+++ "b/leetcode3/\354\265\234\353\257\274\354\247\200/1329.py"
@@ -0,0 +1,19 @@
+class Solution:
+    def diagonalSort(self, mat: List[List[int]]) -> List[List[int]]:
+        diagonal = defaultdict(list)
+
+        # 1. 같은 대각선끼리 모으기
+        for x in range(len(mat)):
+            for y in range(len(mat[0])):
+                diagonal[x - y].append(mat[x][y])
+
+        # 2. 각 대각선 정렬
+        for key in diagonal:
+            diagonal[key].sort(reverse=True)
+
+        # 3. 다시 mat에 넣기
+        for x in range(len(mat)):
+            for y in range(len(mat[0])):
+                mat[x][y] = diagonal[x - y].pop()
+
+        return mat