diff --git a/Docs/05-SQL-reference/data-types.md b/Docs/05-SQL-reference/data-types.md
index 93b5f378ff..647f57341f 100644
--- a/Docs/05-SQL-reference/data-types.md
+++ b/Docs/05-SQL-reference/data-types.md
@@ -17,23 +17,29 @@ The following table lists the data types supported by StoneDB.
 | Binary string | BINARY, VARBINARY, TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB |
 
 # Integer data types
+
 The following table provides the value range of each integer data type.
 
-| **Data type** | **Bytes of storage** | **Signed** | **Min. value** | **Max. value** |
-| --- | --- | --- | --- | --- |
-| TINYINT | 1 | Yes | -128 | 127 |
-|  |  | No | 0 | 127 |
-| SMALLINT | 2 | Yes | -32768 | 32767 |
-|  |  | No | 0 | 32767 |
-| MEDIUMINT | 3 | Yes | -8388608 | 8388607 |
-|  |  | No | 0 | 8388607 |
-| INT | 4 | Yes | -2147483647 | 2147483647 |
-|  |  | No | 0 | 2147483647 |
-| BIGINT | 8 | Yes | -9223372036854775806 | 9223372036854775807 |
-|  |  | No | 0 | 9223372036854775807 |
+Type | Storage (Bytes) | Minimum Value Signed | Minimum Value Unsigned | Maximum Value Signed | Maximum Value Unsigned
+-- | -- | -- | -- | -- | --
+TINYINT | 1 | -128 | 0 | 127 | 255
+SMALLINT | 2 | -32768 | 0 | 32767 | 65535
+MEDIUMINT | 3 | -8388608 | 0 | 8388607 | 16777215
+INT | 4 | -2147483647 | 0 | 2147483647 | 4294967295
+BIGINT  | 8 | -9223372036854775806 | 0 | 9223372036854775807 | 9223372036854775807
+
+**Notice**:
+
+For `INT` type: `-2147483648` is reserved to indicate `INT_NULL` in `Tianmu` engine, `Minimum Value Signed` start from -2147483647.
+
+For `BIGINT` type: `-9223372036854775807` is reserved to indicate `BIGINT_NULL` in `Tianmu`, `Maximum Value Signed` start from -9223372036854775806.
+
+For `BIGINT` type: Maximum Value Unsigned currently limited to 9223372036854775807, we'll expand it to 18446744073709551615 in the future.
 
 On StoneDB, the precision for DECIMAL numbers cannot be higher than 18. For example, if you specify **decimal(19)** in your code, an error will be reported. **DECIMAL(6, 2)** indicates that up to 6 places are supported at the left of the decimal and up to 2 at the right, and thus the value range is [-9999.99, 9999.99].
+
 # String data types
+
 The storage required for a string varies according to the character set in use. The length range also differs. The following table describes the length range of each string data type when character set latin1 is in use.
 
 | **Data type** | **Size** |
@@ -46,6 +52,7 @@ The storage required for a string varies according to the character set in use.
 | LONGTEXT | [0, 4294967295] |
 
 # Date and time data types
+
 The following table describes the value range of each date and time data type.
 
 | **Data type** | **Format** | **Min. value** | **Max. value** |
@@ -54,4 +61,4 @@ The following table describes the value range of each date and time data type.
 | TIME | HH:MM:SS | -838:59:59 | 838:59:59 |
 | DATE | YYYY-MM-DD | 0000-00-00 | 9999-12-31 |
 | DATETIME | YYYY-MM-DD HH:MM:SS | 0000-00-00 00:00:00 | 9999-12-31 23:59:59 |
-| TIMESTAMP | YYYY-MM-DD HH:MM:SS | 1970-01-01 08:00:01 | 2038-01-19 11:14:07 |
\ No newline at end of file
+| TIMESTAMP | YYYY-MM-DD HH:MM:SS | 1970-01-01 08:00:01 | 2038-01-19 11:14:07 |
diff --git a/website/i18n/zh/docusaurus-plugin-content-docs/current/05-SQL-reference/data-types.md b/website/i18n/zh/docusaurus-plugin-content-docs/current/05-SQL-reference/data-types.md
index 1e4c79a3c1..1d4c3caf4a 100644
--- a/website/i18n/zh/docusaurus-plugin-content-docs/current/05-SQL-reference/data-types.md
+++ b/website/i18n/zh/docusaurus-plugin-content-docs/current/05-SQL-reference/data-types.md
@@ -16,22 +16,31 @@ StoneDB 支持如下的数据类型：
 | 字符串型 | CHAR、VARCHAR、TINYTEXT、TEXT、MEDIUMTEXT、LONGTEXT |
 | 二进制字符串型 | BINARY、VARBINARY、TINYBLOB、BLOB、MEDIUMBLOB、LONGBLOB |
 
+# 整型数据类型
+
 各整型的取值范围如下：
 
-| 类型 | 字节 | 有/无符号 | 最小值 | 最大值 |
-| --- | --- | --- | --- | --- |
-| TINYINT | 1 | 有符号 | -128 | 127 |
-|  |  | 无符号 | 0 | 127 |
-| SMALLINT | 2 | 有符号 | -32768 | 32767 |
-|  |  | 无符号 | 0 | 32767 |
-| MEDIUMINT | 3 | 有符号 | -8388608 | 8388607 |
-|  |  | 无符号 | 0 | 8388607 |
-| INT | 4 | 有符号 | -2147483647 | 2147483647 |
-|  |  | 无符号 | 0 | 2147483647 |
-| BIGINT | 8 | 有符号 | -9223372036854775806 | 9223372036854775807 |
-|  |  | 无符号 | 0 | 9223372036854775807 |
-
-DECIMAL 精度必须小于或等于18，否则不支持，如 decimal(19) 就会报错。DECIMAL(6, 2) 表示整数部分和小数部分最大有效位数分别为4和2，所以值域为 [-9999.99, 9999.99]。<br />不同的字符集，即使长度相同，但占用的存储空间不同，以下是以字符集为 latin1 的字符串类型的大小范围。
+类型 | 存储(字节) | 有符号最小值 | 无符号最小值 | 有符号最大值 | 无符号最大值
+-- | -- | -- | -- | -- | --
+TINYINT | 1 | -128 | 0 | 127 | 255
+SMALLINT | 2 | -32768 | 0 | 32767 | 65535
+MEDIUMINT | 3 | -8388608 | 0 | 8388607 | 16777215
+INT | 4 | -2147483647 | 0 | 2147483647 | 4294967295
+BIGINT  | 8 | -9223372036854775806 | 0 | 9223372036854775807 | 9223372036854775807
+
+**注意**：
+
+`INT` 类型： `-2147483648` 在 `Tianmu` 引擎中预留给 `INT_NULL`，有符号最小值从 -2147483647 开始。
+
+`BIGINT` 类型： `-9223372036854775807` 在 `Tianmu` 引擎中预留给 `BIGINT_NULL`，有符号最小值从 -9223372036854775806 开始。
+
+`BIGINT` 类型： 无符号号最大值限制在 9223372036854775807, 未来我们会扩展到 18446744073709551615。
+
+DECIMAL 精度必须小于或等于18，否则不支持，如 decimal(19) 就会报错。DECIMAL(6, 2) 表示整数部分和小数部分最大有效位数分别为4和2，所以值域为 [-9999.99, 9999.99]。
+
+# 字符串类型
+
+不同的字符集，即使长度相同，但占用的存储空间不同，以下是以字符集为 latin1 的字符串类型的大小范围。
 
 | 类型 | 大小 |
 | --- | --- |
@@ -42,6 +51,8 @@ DECIMAL 精度必须小于或等于18，否则不支持，如 decimal(19) 就会
 | MEDIUMTEXT | [0,16777215] |
 | LONGTEXT | [0,4294967295] |
 
+# 日期和时间类型
+
 日期类型的日期范围如下：
 
 | 类型 | 日期格式 | 最小值 | 最大值 |
@@ -50,4 +61,4 @@ DECIMAL 精度必须小于或等于18，否则不支持，如 decimal(19) 就会
 | TIME | HH:MM:SS | -838:59:59 | 838:59:59 |
 | DATE | YYYY-MM-DD | 0000-00-00 | 9999-12-31 |
 | DATETIME | YYYY-MM-DD HH:MM:SS | 0000-00-00 00:00:00 | 9999-12-31 23:59:59 |
-| TIMESTAMP | YYYY-MM-DD HH:MM:SS | 1970-01-01 08:00:01 | 2038-01-19 11:14:07 |
\ No newline at end of file
+| TIMESTAMP | YYYY-MM-DD HH:MM:SS | 1970-01-01 08:00:01 | 2038-01-19 11:14:07 |