A scheduling apparatus for a base transceiver system (BTS), determines a point of data transmission to mobile stations (MSs). The BTS includes buffers for storing data to be transmitted to the MSs. A scheduler determines a priority of each of the MSs taking into account a data rate determined depending on a channel condition between the BTS and the MSs, a required amount of transmission data, and an amount of data to be transmitted to the MSs, and determines an MS having the highest priority among the MSs, as a destination MS to which data is to be transmitted by the BTS. The scheduler increases the required amount of transmission data upon receipt of a retransmitted data packet, and decreases the required amount of transmission data after transmitting data to the MSs.