diff --git a/problems/0509.斐波那契数.md b/problems/0509.斐波那契数.md
index d339940c..1d17784d 100644
--- a/problems/0509.斐波那契数.md
+++ b/problems/0509.斐波那契数.md
@@ -245,7 +245,29 @@ var fib = function(n) {
 };
 ```
 
+TypeScript
+
+```typescript
+function fib(n: number): number {
+    /**
+        dp[i]: 第i个斐波那契数
+        dp[0]: 0;
+        dp[1]：1；
+        ...
+        dp[i] = dp[i - 1] + dp[i - 2];
+     */
+    const dp: number[] = [];
+    dp[0] = 0;
+    dp[1] = 1;
+    for (let i = 2; i <= n; i++) {
+        dp[i] = dp[i - 1] + dp[i - 2];
+    }
+    return dp[n];
+};
+```
+
 ### C
+
 动态规划:
 ```c
 int fib(int n){