The present invention discloses a portable Karaoke system. The portable Karaoke system has a separate radio auxiliary microphone receiving module and a separate FM transmission module, which can be inserted/separated into/from the portable Karaoke system, such that a user can select and purchase only a required function module and easily carry and keep the portable Karaoke system. The portable system has hooks, which are provided at both sides of a battery case to prevent a battery from being easily separated from the battery case, and semicircular recesses, which are formed at the top edges of both sidewalls of the battery case to allow a user to easily remove the battery from the battery case. Furthermore, the portable Karaoke system has first and second gears formed at stepped portions of the end of a microphone body such that the first gear is combined with a general microphone and the second gear is combined with a ball-type microphone net.