Disclosed herein is a disc loading device applied to small-sized and slim type disc players. The disc loading device may include a first guide lever, a second guide lever, a trigger lever, a chucking unit, a slider, and a connecting unit. The connecting unit may be selectively operatively connected to the second guide lever, upon loading a first disc or a second disc, to change a timing at which a rotational force of the trigger lever may be transmitted to the slider.