diff --git a/README.md b/README.md
index c1f978513..c76ea097a 100644
--- a/README.md
+++ b/README.md
@@ -109,11 +109,11 @@ React.render(<Table columns={columns} data={data} />, mountNode);
     </tr>
     <tr>
       <td>rowKey</td>
-      <td>string or Function(record, index):string</td>
+      <td>string or Function(record):string</td>
       <td>'key'</td>
       <td>
         If rowKey is string, `record[rowKey]` will be used as key.
-        If rowKey is function, the return value of `rowKey(record, index)` will be use as key.
+        If rowKey is function, the return value of `rowKey(record)` will be use as key.
       </td>
     </tr>
     <tr>
diff --git a/package.json b/package.json
index 0e7789cb5..84d436cab 100644
--- a/package.json
+++ b/package.json
@@ -56,7 +56,8 @@
   "dependencies": {
     "object-path": "^0.11.1",
     "rc-util": "3.x",
-    "shallowequal": "^0.2.2"
+    "shallowequal": "^0.2.2",
+    "warning": "^3.0.0"
   },
   "devDependencies": {
     "expect.js": "~0.3.1",
diff --git a/src/Table.jsx b/src/Table.jsx
index 04b52ceb8..420de16f0 100644
--- a/src/Table.jsx
+++ b/src/Table.jsx
@@ -1,7 +1,7 @@
 import React, { PropTypes } from 'react';
 import TableRow from './TableRow';
 import TableHeader from './TableHeader';
-import { measureScrollbar, debounce } from './utils';
+import { measureScrollbar, debounce, warningOnce } from './utils';
 import shallowequal from 'shallowequal';
 import addEventListener from 'rc-util/lib/Dom/addEventListener';
 import ColumnManager from './ColumnManager';
@@ -77,7 +77,7 @@ const Table = React.createClass({
     if (props.defaultExpandAllRows) {
       for (let i = 0; i < rows.length; i++) {
         const row = rows[i];
-        expandedRowKeys.push(this.getRowKey(row));
+        expandedRowKeys.push(this.getRowKey(row, i));
         rows = rows.concat(row[props.childrenColumnName] || []);
       }
     } else {
@@ -141,25 +141,25 @@ const Table = React.createClass({
     this.props.onExpandedRowsChange(expandedRowKeys);
   },
 
-  onExpanded(expanded, record, e) {
+  onExpanded(expanded, record, e, index) {
     if (e) {
       e.preventDefault();
       e.stopPropagation();
     }
     const info = this.findExpandedRow(record);
     if (typeof info !== 'undefined' && !expanded) {
-      this.onRowDestroy(record);
+      this.onRowDestroy(record, index);
     } else if (!info && expanded) {
       const expandedRows = this.getExpandedRows().concat();
-      expandedRows.push(this.getRowKey(record));
+      expandedRows.push(this.getRowKey(record, index));
       this.onExpandedRowsChange(expandedRows);
     }
     this.props.onExpand(expanded, record);
   },
 
-  onRowDestroy(record) {
+  onRowDestroy(record, rowIndex) {
     const expandedRows = this.getExpandedRows().concat();
-    const rowKey = this.getRowKey(record);
+    const rowKey = this.getRowKey(record, rowIndex);
     let index = -1;
     expandedRows.forEach((r, i) => {
       if (r === rowKey) {
@@ -174,10 +174,14 @@ const Table = React.createClass({
 
   getRowKey(record, index) {
     const rowKey = this.props.rowKey;
-    if (typeof rowKey === 'function') {
-      return rowKey(record, index);
-    }
-    return typeof record[rowKey] !== 'undefined' ? record[rowKey] : index;
+    const key = (typeof rowKey === 'function') ?
+      rowKey(record, index) : record[rowKey];
+    warningOnce(
+      key !== undefined,
+      'Each record in table should have a unique `key` prop,' +
+      'or set `rowKey` to an unique primary key.'
+    );
+    return key;
   },
 
   getExpandedRows() {
@@ -299,7 +303,7 @@ const Table = React.createClass({
       const record = data[i];
       const key = this.getRowKey(record, i);
       const childrenColumn = record[childrenColumnName];
-      const isRowExpanded = this.isRowExpanded(record);
+      const isRowExpanded = this.isRowExpanded(record, i);
       let expandedRowContent;
       if (expandedRowRender && isRowExpanded) {
         expandedRowContent = expandedRowRender(record, i, indent);
@@ -598,13 +602,13 @@ const Table = React.createClass({
     }
   },
 
-  findExpandedRow(record) {
-    const rows = this.getExpandedRows().filter(i => i === this.getRowKey(record));
+  findExpandedRow(record, index) {
+    const rows = this.getExpandedRows().filter(i => i === this.getRowKey(record, index));
     return rows[0];
   },
 
-  isRowExpanded(record) {
-    return typeof this.findExpandedRow(record) !== 'undefined';
+  isRowExpanded(record, index) {
+    return typeof this.findExpandedRow(record, index) !== 'undefined';
   },
 
   detectScrollTarget(e) {
diff --git a/src/TableRow.jsx b/src/TableRow.jsx
index 6c3898b02..781d08b49 100644
--- a/src/TableRow.jsx
+++ b/src/TableRow.jsx
@@ -60,7 +60,8 @@ const TableRow = React.createClass({
   },
 
   componentWillUnmount() {
-    this.props.onDestroy(this.props.record);
+    const { record, onDestroy, index } = this.props;
+    onDestroy(record, index);
     if (this.unsubscribe) {
       this.unsubscribe();
     }
@@ -77,7 +78,7 @@ const TableRow = React.createClass({
       onExpand,
     } = this.props;
     if (expandable && expandRowByClick) {
-      onExpand(!expanded, record);
+      onExpand(!expanded, record, index);
     }
     onRowClick(record, index, event);
   },
diff --git a/src/utils.js b/src/utils.js
index f8c44ba3e..f76b1d9de 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -1,3 +1,5 @@
+import warning from 'warning';
+
 let scrollbarWidth;
 
 // Measure scrollbar width for padding body during modal show/hide
@@ -52,3 +54,11 @@ export function debounce(func, wait, immediate) {
     }
   };
 }
+
+const warned = {};
+export function warningOnce(condition, format, args) {
+  if (!warned[format]) {
+    warning(condition, format, args);
+    warned[format] = true;
+  }
+}