A method and apparatus for scheduling the data packets transmitted to a plurality of mobile terminals supporting multiple quality of service (QoS) grades in a multichannel wireless communication system includes a storage device for storing queues and data packets of the mobile stations, the queue and data packets of each of the mobile stations being arranged in an order of the quality of service grades; and a scheduler for allocating resources of multiple channels to the mobile stations based on different scheduling metrics separately applied to the multiple channels according to the quality of service grades, each of the scheduling metrics applied to a particular one of channels being used to select one of the mobile stations whose data packets are transmitted through the particular channel; wherein entire data packets of the mobile stations are transmitted through the multiple channels when the allocation of the channel resources has been completed sequentially for each of the multiple channels.