diff --git a/Algorithms/202. Happy Number/202. Happy Number.go b/Algorithms/202. Happy Number/202. Happy Number.go
new file mode 100644
index 00000000..adf6a0cd
--- /dev/null
+++ b/Algorithms/202. Happy Number/202. Happy Number.go	
@@ -0,0 +1,28 @@
+package leetcode
+
+func isHappy(n int) bool {
+	if n == 0 {
+		return false
+	}
+	res := 0
+	num := n
+	record := map[int]int{}
+	for {
+		for num != 0 {
+			res += (num % 10) * (num % 10)
+			num = num / 10
+		}
+		if _, ok := record[res]; !ok {
+			if res == 1 {
+				return true
+			} else {
+				record[res] = res
+				num = res
+				res = 0
+				continue
+			}
+		} else {
+			return false
+		}
+	}
+}
diff --git a/Algorithms/202. Happy Number/202. Happy Number_test.go b/Algorithms/202. Happy Number/202. Happy Number_test.go
new file mode 100644
index 00000000..f4963e98
--- /dev/null
+++ b/Algorithms/202. Happy Number/202. Happy Number_test.go	
@@ -0,0 +1,47 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question202 struct {
+	para202
+	ans202
+}
+
+// para 是参数
+// one 代表第一个参数
+type para202 struct {
+	one int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans202 struct {
+	one bool
+}
+
+func Test_Problem202(t *testing.T) {
+
+	qs := []question202{
+
+		question202{
+			para202{202},
+			ans202{false},
+		},
+
+		question202{
+			para202{19},
+			ans202{true},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 202------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans202, q.para202
+		fmt.Printf("【input】:%v       【output】:%v\n", p, isHappy(p.one))
+	}
+	fmt.Printf("\n\n\n")
+}
diff --git a/Algorithms/202. Happy Number/README.md b/Algorithms/202. Happy Number/README.md
new file mode 100644
index 00000000..eb22b171
--- /dev/null
+++ b/Algorithms/202. Happy Number/README.md	
@@ -0,0 +1,26 @@
+# [202. Happy Number](https://leetcode.com/problems/happy-number/)
+
+## 题目
+
+Write an algorithm to determine if a number is "happy".
+
+A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.
+
+Example 1:
+
+```c
+Input: 19
+Output: true
+Explanation: 
+12 + 92 = 82
+82 + 22 = 68
+62 + 82 = 100
+12 + 02 + 02 = 1
+```
+
+## 题目大意
+
+判断一个数字是否是“快乐数字”，“快乐数字”的定义是，不断的把这个数字的每个数字的平方和加起来，反复的加，最终如果能有结果是 1，则是“快乐数字”，如果不能得到一，出现了循环，则输出 false。
+
+
+