How I can do this?

Just create textbox objects, and add them to the form. Use for-loop to make sufficient amount of text boxes.

this.SuspendLayout();

for(int i=0; i {
TextBox newBox = new TextBox();
newBox.Size = new Size(100,20);
newBox.Position = new Point(i*20,10);
this.Controls.Add(newBox);

}
this.ResumeLayout();