A method of canceling interference components included in received signals of a base station in a mobile communication system, despreads user data in the order of user data grouped for the unit of transmission rate and sequentially cancels user data which are the same as despread user data by allowing the base station to know transmission rate and user codes of user data transmitted from respective terminals, in case that the respective terminals transmit various user data which require various transmission rates in the mobile communication system of CDMA type. The method includes the steps of correlating user data in parallel using high transmission rate of data and user codes of respective terminals by receiving the user data transmitted from the respective terminals in the base station, the transmission rate of data and user codes of the respective terminals being in advance known by the base station, comparing the correlated resultant values with one another to decode one correlation value having one maximum value, and spreading the one correlation value having the maximum value using the user codes and subtracting user data obtained during spreading step from input user data.