diff --git "a/leetcode3/\354\227\274\355\230\234\354\240\225/1329. Sort the Matrix Diagonally.java" "b/leetcode3/\354\227\274\355\230\234\354\240\225/1329. Sort the Matrix Diagonally.java"
new file mode 100644
index 00000000..b91c22df
--- /dev/null
+++ "b/leetcode3/\354\227\274\355\230\234\354\240\225/1329. Sort the Matrix Diagonally.java"	
@@ -0,0 +1,24 @@
+class Solution {
+    public int[][] diagonalSort(int[][] mat) {
+        int m = mat.length, n = mat[0].length;
+        Map<Integer, PriorityQueue<Integer>> map = new HashMap<>();
+
+        // 1. 대각선별로 값 모으기 (key = row - col)
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                int key = i - j;
+                map.computeIfAbsent(key, k -> new PriorityQueue<>()).offer(mat[i][j]);
+            }
+        }
+
+        // 2. 정렬된 값 다시 채워넣기
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                int key = i - j;
+                mat[i][j] = map.get(key).poll();
+            }
+        }
+
+        return mat;
+    }
+}