i have created datagridview dynamically with check box column,once i refresh my datagrid its removes all data except checkbox column,below code for adding checkbox column in datagrid DataGridViewCheckBoxColumn chk = new DataGridViewCheckBoxColumn(); dataGridView1.Columns.Add(chk); chk.HeaderText = "Check Data"; chk.Name = "chk"; int count = dataGridView1.Rows.Count; for (int i = 0; i < count; i++) { dataGridView1.Rows[i].Cells[12].Value = false; } and below code for clearing my datagrid,if i try to add new data in datagridview after refresh still old check box exists and it keeps adding one more checkbox column. dataGridView1.Rows.Clear(); dataGridView1.Refresh(); any suggestion???