Abstract: A card punch of the type having a rectangular hole punching unit driven by an operating handle through a transmission shaft to punch rectangular holes on loose leaves, the improvement comprising two driven gears meshed with two drive gears at two opposite ends of the transmission shaft, a sliding bar driven by the driven gears to force circular punching elements into holes on locating frames, which are fixed to a guide plate between two upright end plates of the base of the card punch, to punch holes on paper being inserted into the locating frames.