diff --git a/Algorithms/0033. Search in Rotated Sorted Array/33. Search in Rotated Sorted Array.go b/Algorithms/0033. Search in Rotated Sorted Array/33. Search in Rotated Sorted Array.go
new file mode 100644
index 00000000..9ce3fee4
--- /dev/null
+++ b/Algorithms/0033. Search in Rotated Sorted Array/33. Search in Rotated Sorted Array.go	
@@ -0,0 +1,34 @@
+package leetcode
+
+func search33(nums []int, target int) int {
+	if len(nums) == 0 {
+		return -1
+	}
+	low, high := 0, len(nums)-1
+	for low <= high {
+		mid := low + (high-low)>>1
+		if nums[mid] == target {
+			return mid
+		} else if nums[mid] > nums[low] { // 在数值大的一部分区间里
+			if nums[low] <= target && target < nums[mid] {
+				high = mid - 1
+			} else {
+				low = mid + 1
+			}
+		} else if nums[mid] < nums[high] { // 在数值小的一部分区间里
+			if nums[mid] < target && target <= nums[high] {
+				low = mid + 1
+			} else {
+				high = mid - 1
+			}
+		} else {
+			if nums[low] == nums[mid] {
+				low++
+			}
+			if nums[high] == nums[mid] {
+				high--
+			}
+		}
+	}
+	return -1
+}
diff --git a/Algorithms/0033. Search in Rotated Sorted Array/33. Search in Rotated Sorted Array_test.go b/Algorithms/0033. Search in Rotated Sorted Array/33. Search in Rotated Sorted Array_test.go
new file mode 100644
index 00000000..3fcfbb5a
--- /dev/null
+++ b/Algorithms/0033. Search in Rotated Sorted Array/33. Search in Rotated Sorted Array_test.go	
@@ -0,0 +1,53 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question33 struct {
+	para33
+	ans33
+}
+
+// para 是参数
+// one 代表第一个参数
+type para33 struct {
+	nums   []int
+	target int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans33 struct {
+	one int
+}
+
+func Test_Problem33(t *testing.T) {
+
+	qs := []question33{
+
+		question33{
+			para33{[]int{3, 1}, 1},
+			ans33{1},
+		},
+
+		question33{
+			para33{[]int{4, 5, 6, 7, 0, 1, 2}, 0},
+			ans33{4},
+		},
+
+		question33{
+			para33{[]int{4, 5, 6, 7, 0, 1, 2}, 3},
+			ans33{-1},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 33------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans33, q.para33
+		fmt.Printf("【input】:%v    【output】:%v\n", p, search33(p.nums, p.target))
+	}
+	fmt.Printf("\n\n\n")
+}
diff --git a/Algorithms/0033. Search in Rotated Sorted Array/README.md b/Algorithms/0033. Search in Rotated Sorted Array/README.md
new file mode 100755
index 00000000..6f69b743
--- /dev/null
+++ b/Algorithms/0033. Search in Rotated Sorted Array/README.md	
@@ -0,0 +1,36 @@
+# [33. Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/)
+
+## 题目:
+
+Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
+
+(i.e., `[0,1,2,4,5,6,7]` might become `[4,5,6,7,0,1,2]`).
+
+You are given a target value to search. If found in the array return its index, otherwise return `-1`.
+
+You may assume no duplicate exists in the array.
+
+Your algorithm's runtime complexity must be in the order of *O*(log *n*).
+
+**Example 1:**
+
+    Input: nums = [4,5,6,7,0,1,2], target = 0
+    Output: 4
+
+**Example 2:**
+
+    Input: nums = [4,5,6,7,0,1,2], target = 3
+    Output: -1
+
+
+## 题目大意
+
+假设按照升序排序的数组在预先未知的某个点上进行了旋转。( 例如，数组 [0,1,2,4,5,6,7] 可能变为 [4,5,6,7,0,1,2] )。搜索一个给定的目标值，如果数组中存在这个目标值，则返回它的索引，否则返回 -1 。你可以假设数组中不存在重复的元素。
+
+你的算法时间复杂度必须是 O(log n) 级别。
+
+
+## 解题思路
+
+- 给出一个数组，数组中本来是从小到大排列的，并且数组中没有重复数字。但是现在把后面随机一段有序的放到数组前面，这样形成了前后两端有序的子序列。在这样的一个数组里面查找一个数，设计一个 O(log n) 的算法。如果找到就输出数组的小标，如果没有找到，就输出 -1 。
+- 由于数组基本有序，虽然中间有一个“断开点”，还是可以使用二分搜索的算法来实现。现在数组前面一段是数值比较大的数，后面一段是数值偏小的数。如果 mid 落在了前一段数值比较大的区间内了，那么一定有 `nums[mid] > nums[low]`，如果是落在后面一段数值比较小的区间内，`nums[mid] ≤ nums[low]` 。如果 mid 落在了后一段数值比较小的区间内了，那么一定有 `nums[mid] < nums[high]`，如果是落在前面一段数值比较大的区间内，`nums[mid] ≤ nums[high]` 。还有 `nums[low] == nums[mid]` 和 `nums[high] == nums[mid]` 的情况，单独处理即可。最后找到则输出 mid，没有找到则输出 -1 。