Thanks a ton mike ..so far i have been sorting the column by adding it to the collection of sorted columns and then doing groupby ....   

 I would probably set the GroupByMode first, before you add the column to the SortedColumns collection. Then you will not need to call RefreshSort.

But again, I am really not clear on what the problem is.  What exactly is the problem? What exactly do you mean by "Not Sorted Properly?"  How are they sorted? What's wrong with the way they are sorted? That's not enough information here for my to begin to guess what the issue is.

Mike i have found the cause ..... the problem is the column by which i am grouping is not sorted properly though i use this statement

grd.DisplayLayout.Bands(0).SortedColumns("PNumber").GroupByMode = GroupByMode.Value

grd.DisplayLayout.Bands(0).SortedColumns.RefreshSort(True)

it s a readonly grid ..does this have anythng to do with this