Thanks. It worked

As I said above, you would set the Value of the cell in the InitializeRow event. Something like this:

        private void ultraGrid1_InitializeLayout(object sender, Infragistics.Win.UltraWinGrid.InitializeLayoutEventArgs e)
        {
            UltraGridColumn delColumn = e.Layout.Bands[0].Columns.Add("Del");
            delColumn.Style = Infragistics.Win.UltraWinGrid.ColumnStyle.Button;
            delColumn.ButtonDisplayStyle = Infragistics.Win.UltraWinGrid.ButtonDisplayStyle.Always;
        }

        private void ultraGrid1_InitializeRow(object sender, InitializeRowEventArgs e)
        {
            if (e.Row.Cells.Exists("Del"))
            {
                e.Row.Cells["Del"].Value = "Del";
            }
        }

thanks for your  replay.

My mean is, in this column(DeletingColumn), we need button for handle edit/delete event,so our code like above wrote.

this way can add a column with buttons,but I cann't add text on the button.like the image below.Did have any way to do this? if possible, give me some sample code.thanks.

What kind of button style are you referring to? I don't know what you mean by style. 

Regarding the text, you can set the Value of the cell, just as you would for any other cell. The InitializeRow event is a good place to do this.

DeletingColumn.CellButtonDisplay = CellButtonDisplay.Always;