利用<td rowspan = "num"/>;原理来实现，其中num为要合并的行数。
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<style>
td{
border:1px solid red;
}
</style>
</head>
<body>
<table class="table mbn tc-med-1 tc-bold-last tc-fs13-last" id="table1">
<thead>
<tr>
<th>品牌</th>
<th>车型</th>
<th>性别</th>
<th>配额数</th>
<th>完成数</th>
</tr>
</thead>
<tbody>
<tr>
<td>宝马</td>
<td>3系</td>
<td>男</td>
<td>200</td>
<td>100</td>
</tr>
<tr>
<td>宝马</td>
<td>3系</td>
<td>女</td>
<td>100</td>
<td>57</td>
</tr>
<tr>
<td>宝马</td>
<td>5系</td>
<td>男</td>
<td>100</td>
<td>68</td>
</tr>
<tr>
<td>宝马</td>
<td>5系</td>
<td>女</td>
<td>200</td>
<td>94</td>
</tr>
<tr>
<td >宝马</td>
<td>7系</td>
<td>男</td>
<td>100</td>
<td>68</td>
</tr>
<tr>
<td>宝马</td>
<td>7系</td>
<td>女</td>
<td>100</td>
<td>68</td>
</tr>
</tbody>
</table>
</body>
</html>
<script src="design/static/js/jquery.js"></script>
<script src="design/static/js/jquery-ui-1.10.min.js"></script>
<script>
jQuery.fn.rowspan = function(colIdx) { //封装的一个JQuery小插件
return this.each(function(){
var that;
$(‘tr‘, this).each(function(row) {
$(‘td:eq(‘+colIdx+‘)‘, this).filter(‘:visible‘).each(function(col) {
if (that!=null && $(this).html() == $(that).html()) {
rowspan = $(that).attr("rowSpan");
if (rowspan == undefined) {
$(that).attr("rowSpan",1);
rowspan = $(that).attr("rowSpan"); }
rowspan = Number(rowspan)+1;
$(that).attr("rowSpan",rowspan);
$(this).hide();
} else {
that = this;
}
});
});
});
}
$(function() {
$("#table1").rowspan(0);//传入的参数是对应的列数从0开始
$("#table1").rowspan(1);
$("#table1").rowspan(2);
$("#table1").rowspan(3);
});
</script>
其它几种方法：
<!DOCTYPE html>
<html>
<head>
<title>merge.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<link rel="stylesheet" href="css/jquery-ui.css" />
<script src="design/static/js/jquery.js"></script>
<script src="design/static/js/jquery-ui-1.10.min.js"></script>
<script type="text/javascript">
function merge1(){ //可实现单元格，通过给 开始cell的比较
var totalRow = $("#tbl").find("tr").length;
var totalCol = $("#tbl").find("tr").eq(0).find("td").length;
for(var col=totalCol-1;col>=1;col--){
spanNum =1;
startCell = $("#tbl").find("tr").eq(totalRow-1).find("td").eq(col);
for(var row = totalRow-1;row>=1;row--){
targetCell = $("#tbl").find("tr").eq(row-1).find("td").eq(col);
if(startCell.text() == targetCell.text() && startCell.text()!=""){
spanNum++;
targetCell.attr("rowSpan",spanNum);
startCell.remove();
}else{
spanNum =1;
}
startCell = targetCell;
}
}
}
function merge2() { //可实现合并单元格,上下行来比较
var totalCols = $("#tbl").find("tr:eq(0)").find("td").length;
var totalRows = $("#tbl").find("tr").length;
for ( var i = totalCols-1; i >= 1; i--) {
for ( var j = totalRows-1; j >= 1; j--) {
startCell = $("#tbl").find("tr").eq(j).find("td").eq(i);
targetCell = $("#tbl").find("tr").eq(j - 1).find("td").eq(i);
if (startCell.text() == targetCell.text() && targetCell.text() != "") {
targetCell.attr("rowSpan", (startCell.attr("rowSpan")==undefined)?2:(eval(startCell.attr("rowSpan"))+1));
startCell.remove();
}
}
}
}
/*先合并，使用style 的display:none将相同元素隐藏，然后再remove
*/
function merge3(){
var totalCols = $("#tbl").find("tr:eq(0)").find("td").length;
var totalRows = $("#tbl").find("tr").length;
for(var col=totalCols-1;col>=1;col--){
spanNum =1;
startCell = $("#tbl").find("tr").eq(totalRows-1).find("td").eq(col);
for(var row = totalRows-1;row>=1;row--){
targetCell = $("#tbl").find("tr").eq(row-1).find("td").eq(col);
if(startCell.text() == targetCell.text() && startCell.text()!=""){
spanNum++;
targetCell.attr("rowSpan",spanNum);
startCell.attr("style","visibility:hidden");
// startCell.attr("style","display:none");
}else{
spanNum =1;
}
startCell = targetCell;
}
}
for(var j=totalCols-1;j>=1;j--){
for(var i=totalRows-1;i>=1;i--){
cell = $("#tbl").find("tr").eq(i).find("td").eq(j);
if(cell.attr("style")!=undefined){
if(cell.attr("style")=="visibility:hidden"){
cell.remove();
}
}
}
}
}
function merge4(){ //与merge3方法类似，目的是看一下 display:none与visibility:hidden的效果区别
var totalCols = $("#tbl").find("tr:eq(0)").find("td").length;
var totalRows = $("#tbl").find("tr").length;
for(var col=totalCols-1;col>=1;col--){
spanNum =1;
startCell = $("#tbl").find("tr").eq(totalRows-1).find("td").eq(col);
for(var row = totalRows-1;row>=1;row--){
targetCell = $("#tbl").find("tr").eq(row-1).find("td").eq(col);
if(startCell.text() == targetCell.text() && startCell.text()!=""){
spanNum++;
targetCell.attr("rowSpan",spanNum);
startCell.attr("style","display:none");
// startCell.attr("style","display:none");
}else{
spanNum =1;
}
startCell = targetCell;
}
}
for(var j=totalCols-1;j>=1;j--){
for(var i=totalRows-1;i>=1;i--){
cell = $("#tbl").find("tr").eq(i).find("td").eq(j);
if(cell.attr("style")!=undefined){
if(cell.attr("style")=="display:none"){
cell.remove();
}
}
}
}
}
</script>
</head>
<body>
<table id="tbl" cellpadding="3" border=1>
<thead>
<tr>
<td>销售时间</td>
<td>裙子</td>
<td>裤子</td>
<td>风衣</td>
<td>鞋子</td>
</tr>
</thead>
<tbody>
<tr>
<td>8:00-9:00</td>
<td>3</td>
<td>2</td>
<td>4</td>
<td>3</td>
</tr>
<tr>
<td>9:00-10:00</td>
<td>3</td>
<td>2</td>
<td>5</td>
<td>3</td>
</tr>
<tr>
<td>10:00-11:00</td>
<td>3</td>
<td>2</td>
<td>5</td>
<td>1</td>
</tr>
<tr>
<td>11:00-12:00</td>
<td>2</td>
<td>2</td>
<td>4</td>
<td>1</td>
</tr>
</tbody>
</table>
<input type="button" value="合并" id="merge" onclick="merge2();">
</body>
</html>
原文：http://www.cnblogs.com/haoxl/p/5658772.html