Abstract: A method for discriminating a disc includes the steps of: detecting that the disc is inserted into an optical drive; starting a roller motor to load the disc; counting the number of operating sensors; counting time of a disk loading procedure; judging whether all of the sensors operate to determine the disc is a primary disc; judging whether the number of the operating sensors decreases to determine the disc is a secondary disc; determining whether a disc loading time exceeds a default time by comparison; and ejecting the disc. If the number of operating sensors is kept the same as the original one and the time of the loading procedure does not exceed a default value, the method goes back to the judging steps to discriminate the disc repeatedly. If the disc loading time exceeds the default time, the disc is ejected.