Hi Dear use this technique.
private void CreateTextBox()
{
for (int i = 0; i < 3; i++)
{
TextBox txtBox = new TextBox();
txtBox.ID = "Txt" + Convert.ToString(i + 1);
txtBox.Text = "TextBox" + Convert.ToString(i + 1);
this.Panel1.Controls.Add(txtBox);
}
}