diff --git a/components/list/Item.tsx b/components/list/Item.tsx
index e13d00ea31..e7f84a1704 100644
--- a/components/list/Item.tsx
+++ b/components/list/Item.tsx
@@ -2,7 +2,7 @@ import * as React from 'react';
 import PropTypes from 'prop-types';
 import classNames from 'classnames';
 import { Col } from '../grid';
-import { ListGridType } from './index';
+import { ListGridType, ColumnType } from './index';
 
 export interface ListItemProps {
   className?: string;
@@ -51,8 +51,8 @@ export const Meta = (props: ListItemMetaProps) => {
   );
 };
 
-function getGrid(grid, t) {
-  return grid[t] && Math.floor(24 / grid[t]);
+function getGrid(grid: ListGridType, t: ColumnType) {
+  return grid[t] && Math.floor(24 / grid[t]!);
 }
 
 const GridColumns = ['', 1, 2, 3, 4, 6, 8, 12, 24];
@@ -99,7 +99,7 @@ export default class Item extends React.Component<ListItemProps, any> {
 
     let actionsContent;
     if (actions && actions.length > 0) {
-      const actionsContentItem = (action, i) => (
+      const actionsContentItem = (action: React.ReactNode, i: number) => (
         <li key={`${prefixCls}-item-action-${i}`}>
           {action}
           {i !== (actions.length - 1) && <em className={`${prefixCls}-item-action-split`}/>}
diff --git a/components/list/index.tsx b/components/list/index.tsx
index 1ea6180c14..2e4dbc672a 100644
--- a/components/list/index.tsx
+++ b/components/list/index.tsx
@@ -12,16 +12,18 @@ import Item from './Item';
 
 export { ListItemProps, ListItemMetaProps } from './Item';
 
-export type ColumnType = 1 | 2 | 3 | 4 | 6 | 8 | 12 | 24;
+export type ColumnCount = 1 | 2 | 3 | 4 | 6 | 8 | 12 | 24;
+
+export type ColumnType = 'gutter' | 'column' | 'xs' | 'sm' | 'md' | 'lg' | 'xl';
 
 export interface ListGridType {
   gutter?: number;
-  column?: ColumnType;
-  xs?: ColumnType;
-  sm?: ColumnType;
-  md?: ColumnType;
-  lg?: ColumnType;
-  xl?: ColumnType;
+  column?: ColumnCount;
+  xs?: ColumnCount;
+  sm?: ColumnCount;
+  md?: ColumnCount;
+  lg?: ColumnCount;
+  xl?: ColumnCount;
 }
 
 export type ListSize = 'small' | 'default' | 'large';
@@ -48,6 +50,10 @@ export interface ListProps {
   locale?: Object;
 }
 
+export interface ListLocale {
+  emptyText: string;
+}
+
 export default class List extends React.Component<ListProps> {
   static Item: typeof Item = Item;
 
@@ -64,7 +70,7 @@ export default class List extends React.Component<ListProps> {
     pagination: false,
   };
 
-  private keys = {};
+  private keys: {[key: string]: string} = {};
 
   getChildContext() {
     return {
@@ -72,7 +78,7 @@ export default class List extends React.Component<ListProps> {
     };
   }
 
-  renderItem = (item, index) => {
+  renderItem = (item: React.ReactElement<any>, index: number) => {
     const { dataSource, renderItem, rowKey } = this.props;
     let key;
 
@@ -98,7 +104,7 @@ export default class List extends React.Component<ListProps> {
     return !!(loadMore || pagination || footer);
   }
 
-  renderEmpty = (contextLocale) => {
+  renderEmpty = (contextLocale: ListLocale) => {
     const locale = { ...contextLocale, ...this.props.locale };
     return <div className={`${this.props.prefixCls}-empty-text`}>{locale.emptyText}</div>;
   }
@@ -155,8 +161,8 @@ export default class List extends React.Component<ListProps> {
 
     let childrenContent;
     if (dataSource.length > 0) {
-      const childrenList = React.Children.map(dataSource.map((item: any, index) => this.renderItem(item, index)),
-        (child: any, index) => React.cloneElement(child, {
+      const items = dataSource.map((item: any, index: number) => this.renderItem(item, index));
+      const childrenList = React.Children.map(items, (child: any, index) => React.cloneElement(child, {
           key: this.keys[index],
         }),
       );