diff --git a/list.go b/list.go
new file mode 100644
index 0000000..cd856df
--- /dev/null
+++ b/list.go
@@ -0,0 +1,17 @@
+package cacheMemory
+
+type List[T any] struct {
+	items map[string]*T
+}
+
+// SetIfNotExists 写入缓存，如果Key不存在
+func (receiver *List[T]) SetIfNotExists(key string, getItem func() *T) {
+	if _, isExists := receiver.items[key]; !isExists {
+		receiver.items[key] = getItem()
+	}
+}
+
+// Get 获取数据
+func (receiver *List[T]) Get(key string) *T {
+	return receiver.items[key]
+}