This example shows how to assign percentage width to a column in DataGrid.
<table id="dg" class="easyui-datagrid" title="Fluid DataGrid" style="width:700px;height:250px"
data-options="
singleSelect:true,
collapsible:true,
url:'examples/datagrid/datagrid_data1.json',
method:'get'
">
<thead>
<tr>
<th data-options="field:'itemid',resizable:false" width="15%">Item ID(15%)</th>
<th data-options="field:'productid',resizable:false" width="15%">Product(15%)</th>
<th data-options="field:'listprice',align:'right',resizable:false" width="15%">List Price(15%)</th>
<th data-options="field:'unitcost',align:'right',resizable:false" width="15%">Unit Cost(15%)</th>
<th data-options="field:'attr1',resizable:false" width="25%">Attribute(25%)</th>
<th data-options="field:'status',align:'center',resizable:false" width="15%">Status(15%)</th>
</tr>
</thead>
</table>