A sub-code providing method that provides correct sub-code data when sub-code data is requested from a host when a reproduction mode is performed in an optical disc drive. In a method providing sub-code data to a host computer in an optical disc drive formed so that data from a pick-up is reproduced through a buffer, the method includes the operations of setting sub-code data whenever data of a predetermined unit is output from the buffer, and transmitting the set sub-code data to the host computer when the sub-code data is requested from the host computer during the reproduction mode. Therefore, it is possible to provide more accurate sub-code data to the host computer and to thus prevent the reproduction of unnatural screen during operations such as automatic reproduction or game CD reproduction.