Apply a for loop on the grid. Find the check box control from the grid like this:-
for(int i=0;i<grdView.rows.count,i++)>
{
CheckBox chkSel=(CheckBox)grdView.Rows[i].FindControl("chkselect");
if(chkSel.checked==true)
grdView.Rows.RemoveAt(i);
}
Give it a try.