The easiest way to populate jqGrid to XML content is to first load the raw XML data inside an ADO.NET DataSet, and then bind the jqGrid instance to the DataSet.

Here is a practical example - let's say you want to populate the grid with this XML data, located in "data.xml" file:

<?xml version="1.0" encoding="utf-8" ?>
<Employee>
  <em>
    <id>1</id>
    <name>Florian</name>
    <phone>123</phone>
  </em>
  <em>
    <id>2</id>
    <name>Andreas</name>
    <phone>234</phone>
  </em>
  <em>
    <id>3</id>
    <name>Martin</name>
    <phone>345</phone>
  </em>
</Employee>

You just need to drag a jqGrid instance to the ASPX page. Remember to also define the columns.

<trirand:JQGrid ID="XmlGrid" runat="server">
   <Columns>
         <trirand:JQGridColumn DataField="id" />
      <trirand:JQGridColumn DataField="name" />
      <trirand:JQGridColumn DataField="phone" />
   </Columns>
</trirand:JQGrid>

And then read the XML into an ADO.NET DataSet and bind the grid:

protected void Page_Load(object sender, EventArgs e)
{
    DataSet ds = new DataSet();
    ds.ReadXml(Server.MapPath("~/data.xml"));

    XmlGrid.DataSource = ds;
    XmlGrid.DataBind();
}