Can I pass a datatable as parameter of a web service

[WebMethod]
public DataTable ExcelExport(dt)
  {
     DataTable  dt = new DataTable()
     // your Code
     return dt;

  }

//add table to this dataset
DataSet obj = new DataSet();
//create xmlDataDocument object
//pass this xdd object to webservice
XmlDataDocument xdd = new XmlDataDocument(obj);
//get dataset from XmlDataDocument
obj = xdd.DataSet;