diff --git a/RedisStudyTest/RedisStringStudyTest.cs b/RedisStudyTest/RedisStringStudyTest.cs
index 8140b15..8895154 100644
--- a/RedisStudyTest/RedisStringStudyTest.cs
+++ b/RedisStudyTest/RedisStringStudyTest.cs
@@ -327,6 +327,51 @@ namespace RedisStudyTest
         }
         #endregion
 
+        #region StringGetRange
+
+        [Fact]
+        public void StringGetRangeTest()
+        {
+            redisStringStudy.StringSet(defaultRedisKey, "wanggaofeng", TimeSpan.FromSeconds(10));
+
+            var getRange = redisStringStudy.StringGetRange(defaultRedisKey, 2, -1);
+            Assert.Equal("nggaofeng", getRange);
+        }
+
+        #endregion
+
+        #region StringGetSet
+
+        [Fact]
+        public void StringGetSetTest()
+        {
+            //key不存在时，返回null
+            var oldValue = redisStringStudy.StringGetSet(defaultRedisKey, "wanggaofeng");
+            Assert.False(oldValue.HasValue);
+
+            //存在，返回旧值
+            oldValue = redisStringStudy.StringGetSet(defaultRedisKey, "王高峰");
+            Assert.Equal("wanggaofeng", oldValue);
+        }
+
+        #endregion
+
+        #region StringGetWithExpiry
+        [Fact]
+        public void StringGetWithExpiryTest()
+        {
+            redisStringStudy.StringSet(defaultRedisKey, "wanggaofeng", TimeSpan.FromSeconds(20));
+
+            var redisValueWithExpiry =redisStringStudy.StringGetWithExpiry(defaultRedisKey);
+
+            Assert.Equal("wanggaofeng",redisValueWithExpiry.Value);
+            Assert.True(redisValueWithExpiry.Expiry.HasValue);
+            Assert.True(redisValueWithExpiry.Expiry.Value.Seconds <= 20 && redisValueWithExpiry.Expiry.Value.Seconds>=15);
+
+        }
+
+        #endregion
+
         #region 清理
         public void Dispose()
         {