The invention provides a connection structure installed in a data processing apparatus. The data processing apparatus includes a keyboard and a base. The keyboard includes a bottom. The base includes a top plate. The connection structure connects the bottom and the top plate. The connection structure includes a mounted boss and a mounting hole. The mounted boss is disposed on the bottom of the keyboard. The mounted boss includes a groove. The mounting hole is disposed on the top plate of the base. The mounting hole includes a protrusion. When the bottom of the keyboard is assembled to the top of the base, the mounted boss would fit into the mounting hole, such that the protrusion is locked with the groove.