diff --git a/.storybook/webpack.config.js b/.storybook/webpack.config.js
index 2436ed51..3caf0a64 100644
--- a/.storybook/webpack.config.js
+++ b/.storybook/webpack.config.js
@@ -29,7 +29,12 @@ module.exports = async ({ config, mode }) => {
     use: [
       'style-loader',
       'css-loader',
-      'sass-loader',
+      {
+        loader: require.resolve('sass-loader'),
+        options: {
+          precision: 8,
+        }
+      },
     ],
     include: path.resolve(__dirname, '../')
   });
@@ -56,7 +61,12 @@ module.exports = async ({ config, mode }) => {
           },
         },
       },
-      'sass-loader'
+      {
+        loader: require.resolve('sass-loader'),
+        options: {
+          precision: 8,
+        }
+      },
     ],
   },)
   config.resolve.extensions.push('.ts', '.tsx')
diff --git a/docs/content/components/input-dropdown.mdx b/docs/content/components/input-dropdown.mdx
new file mode 100644
index 00000000..cc15a6a7
--- /dev/null
+++ b/docs/content/components/input-dropdown.mdx
@@ -0,0 +1,37 @@
+---
+title: InputDropdown Input 下拉框
+date: 2019-08-23
+author: lijianxin1202
+---
+作为 Input 一部分的下拉框
+
+## 使用方式
+通常和 Input 一起使用，在 Input 的前面或者后部，用来增强 Input 功能
+
+## 基本用法
+
+```jsx
+() => {
+  const [value, updateValue] = React.useState('MB');
+  return (<div style={{ width: '300px' }}>
+    <InputGroup>
+      <FormControl />
+      <InputDropdown
+        pullRight
+        defaultValue="GB"
+        onChange={updateValue}
+        value={value}
+        options={[
+          { title: 'MB', value: 'MB' },
+          { title: 'GB', value: 'GB' },
+          { title: 'TB', value: 'TB' },
+        ]} />
+    </InputGroup>
+  </div>);
+}
+```
+
+## API
+```jsx previewOnly
+<PropTable of="inputDropdown" />
+```
\ No newline at end of file
diff --git a/docs/gatsby-config.js b/docs/gatsby-config.js
index 352774b7..702df995 100644
--- a/docs/gatsby-config.js
+++ b/docs/gatsby-config.js
@@ -65,6 +65,9 @@ module.exports = {
       cssLoaderOptions: {
         camelCase: false,
       },
+      options: {
+        precision: 8,
+      },
     },
   ],
 }
diff --git a/src/components/InputDropdown/index.test.tsx b/src/components/InputDropdown/index.test.tsx
new file mode 100644
index 00000000..e56ba74a
--- /dev/null
+++ b/src/components/InputDropdown/index.test.tsx
@@ -0,0 +1,60 @@
+import React from 'react';
+import InputDropdown from './index';
+import { mount } from 'enzyme';
+import { InputGroup, FormControl } from 'react-bootstrap';
+
+describe('InputDropdown', () => {
+  it('should render corrent dropdown', () => {
+    const Demo = () => {
+      const [value, updateValue] = React.useState('MB');
+      return (<div style={{ width: '300px' }}>
+        <InputGroup>
+          <FormControl />
+          <InputDropdown
+            pullRight
+            defaultValue="GB"
+            onChange={(key: any) => updateValue(key)}
+            value={value}
+            options={[
+              { title: 'MB', value: 'MB' },
+              { title: 'GB', value: 'GB' },
+              { title: 'TB', value: 'TB' },
+            ]} />
+        </InputGroup>
+      </div>);
+    }
+    const dropdown = mount(<Demo />);
+    const button = dropdown.find('button');
+    expect(dropdown.find('.dropdown.input-group-btn').length).toBe(1);
+    button.simulate('click');
+    const tb = dropdown.find('a').at(2);
+    tb.simulate('click');
+    expect(dropdown.find('button[value="TB"]').length).toBe(1);
+  });
+
+  it('should render corrent with input', () => {
+    const Demo = () => {
+      const [value, updateValue] = React.useState('MB');
+      return (<div style={{ width: '300px' }}>
+        <InputGroup>
+          <FormControl />
+          <InputDropdown
+            pullRight
+            input={{ value, onChange: updateValue }}
+            options={[
+              { title: 'MB', value: 'MB' },
+              { title: 'GB', value: 'GB' },
+              { title: 'TB', value: 'TB' },
+            ]} />
+        </InputGroup>
+      </div>);
+    }
+    const dropdown = mount(<Demo />);
+    const button = dropdown.find('button');
+    button.simulate('click');
+    const tb = dropdown.find('a').at(2);
+    tb.simulate('click');
+    // @ts-ignore
+    expect(dropdown.find('button').instance().textContent).toBe('TB ');
+  });
+});
\ No newline at end of file
diff --git a/src/components/InputDropdown/index.tsx b/src/components/InputDropdown/index.tsx
new file mode 100644
index 00000000..3ef8ad2f
--- /dev/null
+++ b/src/components/InputDropdown/index.tsx
@@ -0,0 +1,77 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import { find, get } from 'lodash';
+import { DropdownButton, MenuItem, InputGroup } from 'react-bootstrap';
+import { uuid } from '../../utils';
+import { InputDropdownProps } from '../../interface';
+
+const InputDropdown = (props: InputDropdownProps) => {
+  function getValue() {
+    const { input, value, defaultValue } = props;
+    if (input && input.value !== undefined) {
+      return input.value;
+    }
+    return value !== undefined ? value : defaultValue;
+  }
+
+  function getTitle() {
+    const { options } = props;
+    const option = find(options, { value: getValue() });
+    return get(option, 'title');
+  }
+
+  function handleSelect(eventKey: any) {
+    const { input, onChange } = props;
+    if (onChange) {
+      onChange(eventKey);
+    } else if (input) {
+      input.onChange(eventKey);
+    }
+  }
+  const { input, meta, options, ...rest } = props;
+  return (
+    <DropdownButton
+      id={uuid()}
+      {...rest}
+      componentClass={InputGroup.Button}
+      onSelect={handleSelect}
+      title={getTitle()}
+    >
+      {options &&
+        options.map(option => (
+          <MenuItem key={option.value} eventKey={option.value}>
+            {option.title}
+          </MenuItem>
+        ))}
+    </DropdownButton>
+  );
+}
+
+InputDropdown.propTypes = {
+  /**
+   * 下拉选项
+   **/
+  options: PropTypes.array,
+  /**
+   * 下拉框是否右对齐，默认为 true
+   **/
+  pullRight: PropTypes.bool,
+  /**
+   * 默认值
+   **/
+  defaultValue: PropTypes.string,
+  /**
+   * value 变化后回调
+   **/
+  onChange: PropTypes.func,
+  /**
+   * value，传入 value 时变为受控组件
+   **/
+  value: PropTypes.string,
+};
+
+InputDropdown.defaultProps = {
+  pullRight: true,
+};
+
+export default InputDropdown;
\ No newline at end of file
diff --git a/src/components/index.tsx b/src/components/index.tsx
index 92a7fb9e..e5bd8dd4 100644
--- a/src/components/index.tsx
+++ b/src/components/index.tsx
@@ -3,6 +3,7 @@ import Badge from './Badge';
 import Dropdown from './Dropdown';
 import DropdownButton from './DropdownButton';
 import Icon from './Icon';
+import InputDropdown from './InputDropdown';
 import Loader from './Loader';
 import Modal from './Modal';
 import Navigation from './Navigation';
@@ -28,6 +29,7 @@ export {
   Dropdown,
   DropdownButton,
   Icon,
+  InputDropdown,
   Loader,
   MenuItem,
   Modal,
diff --git a/src/interface.tsx b/src/interface.tsx
index bb0bec32..94a65fa4 100644
--- a/src/interface.tsx
+++ b/src/interface.tsx
@@ -227,6 +227,18 @@ export interface DropdownProps extends DropdownDefaultProps {
   children?: React.ReactNode;
 }
 
+export interface MenuItemOptions {
+  title: string;
+  value: string;
+}
+export interface InputDropdownProps {
+  options?: MenuItemOptions[];
+  defaultValue?: string;
+  value?: string;
+  onChange?: SelectCallback;
+  input?: any;
+  meta?: any;
+}
 export interface Query {
   offset: number;
   limit: number;
diff --git a/stories/InputDropdown.stories.tsx b/stories/InputDropdown.stories.tsx
new file mode 100644
index 00000000..c6bdd98f
--- /dev/null
+++ b/stories/InputDropdown.stories.tsx
@@ -0,0 +1,27 @@
+import React from 'react';
+import { storiesOf } from '@storybook/react';
+import { InputDropdown } from '../src';
+import { FormControl, InputGroup } from 'react-bootstrap';
+
+storiesOf('InputDropdown', module)
+  .add('default', () => {
+    const Demo = () => {
+      const [value, updateValue] = React.useState('MB');
+      return (<div style={{ width: '300px' }}>
+        <InputGroup>
+          <FormControl />
+          <InputDropdown
+            pullRight
+            defaultValue="GB"
+            onChange={(key: any) => updateValue(key)}
+            value={value}
+            options={[
+              { title: 'MB', value: 'MB' },
+              { title: 'GB', value: 'GB' },
+              { title: 'TB', value: 'TB' },
+            ]} />
+        </InputGroup>
+      </div>);
+    }
+    return <Demo />;
+  })
\ No newline at end of file
diff --git a/webpack.config.js b/webpack.config.js
index dd78eb7d..b2da0d15 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -32,7 +32,12 @@ module.exports = {
         use: [
           MiniCssExtractPlugin.loader,
           'css-loader',
-          'sass-loader',
+          {
+            loader: require.resolve('sass-loader'),
+            options: {
+              precision: 8,
+            }
+          },
         ],
       },
       {
@@ -48,7 +53,12 @@ module.exports = {
               },
             },
           },
-          'sass-loader'
+          {
+            loader: require.resolve('sass-loader'),
+            options: {
+              precision: 8,
+            }
+          },
         ],
       },
     ]