tbody添加垂直滚动条

法一：

用2个table：

<table width="300" border="0" cellpadding="0" cellspacing="1" bgcolor="#0099CC">
<tr> 
<th width="25%" nowrap><font color="#FFFFFF"> 123 </th>
<th width="25%" nowrap><font color="#FFFFFF"> 456 </th>
<th width="25%" nowrap><font color="#FFFFFF"> 789 </th>
<th width="25%" nowrap><font color="#FFFFFF"> abc </th>
</tr>
</table>
<span style="overflow-y:auto;height:100px;320px">
<table width="300" border="0" cellpadding="0" cellspacing="1" bgcolor="#0099CC">
<tr bgcolor="#FFFFFF"> 
<td width="25%"> 1</td>

<td width="25%"> 4</td>

<td width="25%"> 7</td>

<td width="25%"> a</td>
</tr>

<tr bgcolor="#FFFFFF"> 
<td > 2</td>

<td > 5</td>

<td> 8</td>

<td> b</td>
</tr>

<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
<tr bgcolor="#FFFFFF"> 
<td> 3 </td>

<td> 6 </td>

<td> 9 </td>

<td > c </td>
</tr>
</table>
</span> 

法二：

1，把tbody设置成display:block，然后就对其高度设置一个固定值，overflow设置成auto。 

2，把thead的tr设置成display:block。 

3，因为都设置成block所以要给td手动添加宽度 200px 

<table class="table"> 
<thead> 
<tr> 
<th>Id</th> 
<th>Name</th> 
<th>Category</th> 
<th>MonthAmount</th> 
<th>hasBackUp</th> 
<th>score</th> 
</tr> 
</thead> 
<tbody> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
<tr> 
<td>23</td> 
<td>South Bearing</td> 
<td>Glass/Material</td> 
<td>1234444</td> 
<td>TRUE</td> 
<td>3456.00</td> 
</tr> 
</tbody> 
</table> 

.table thead tr { 
display:block; 
} 
.table tbody { 
display: block; 
height: 200px; 
overflow: auto; 
} 
.table th { 
width:20%; 
} 
.table td { 
width:20%; 
}