diff --git a/.vscode/settings.json b/.vscode/settings.json
index 14567ee..38e1d7b 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,8 +1,10 @@
 {
   "cSpell.words": [
+    "dvdf",
     "lcci",
     "lcof",
     "nums",
+    "pwwkew",
     "zhong"
   ]
 }
\ No newline at end of file
diff --git a/README.md b/README.md
index 993358f..a60a346 100644
--- a/README.md
+++ b/README.md
@@ -51,6 +51,11 @@ LeetCode 与 LintCode 解题记录。此为个人练习仓库，代码中对重
 
   - LintCode 55. 比较字符串 https://www.lintcode.com/problem/compare-strings/description
 
+- [最长无重复字符的子串](src/string/longest-substring-without-repeating-characters.js)
+
+  - LeetCode 3. 无重复字符的最长子串 https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/
+  - LintCode 384. 最长无重复字符的子串 https://www.lintcode.com/problem/longest-substring-without-repeating-characters/description
+
 ## 数组
 
 - [电话号码的字母组合](src/array/letter-combinations-of-a-phone-number.js)
diff --git a/src/string/longest-substring-without-repeating-characters.js b/src/string/longest-substring-without-repeating-characters.js
new file mode 100644
index 0000000..e9a50b2
--- /dev/null
+++ b/src/string/longest-substring-without-repeating-characters.js
@@ -0,0 +1,15 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+export const lengthOfLongestSubstring = function (s) {
+  let max = 0
+
+  for (let n = 0, len = s.length, inx = 0, set = new Set(); n < len; n++) {
+    if (n !== 0) set.delete(s[n - 1])
+    while (inx < len && !set.has(s[inx])) set.add(s[inx++])
+    max = Math.max(max, inx - n)
+  }
+
+  return max
+}
diff --git a/test/string/longest-substring-without-repeating-characters.test.js b/test/string/longest-substring-without-repeating-characters.test.js
new file mode 100644
index 0000000..10b2ee6
--- /dev/null
+++ b/test/string/longest-substring-without-repeating-characters.test.js
@@ -0,0 +1,11 @@
+import { lengthOfLongestSubstring } from '../../src/string/longest-substring-without-repeating-characters'
+
+test('最长无重复字符的子串', () => {
+  expect(lengthOfLongestSubstring('abcabcbb')).toBe(3)
+  expect(lengthOfLongestSubstring('bbbbb')).toBe(1)
+  expect(lengthOfLongestSubstring('pwwkew')).toBe(3)
+  expect(lengthOfLongestSubstring('')).toBe(0)
+  expect(lengthOfLongestSubstring(' ')).toBe(1)
+  expect(lengthOfLongestSubstring('au')).toBe(2)
+  expect(lengthOfLongestSubstring('dvdf')).toBe(3)
+})