A method and apparatus for controlling an uplink data rate, without increasing downlink signaling overhead, in a mobile communication system that supports an uplink packet data service. A Node B transmits an Absolute grants (AG) using one of first and second IDs to a User Equipment (UE). Upon receipt of an AG with the first UE-ID, the UE transmits uplink data within an allowed maximum data rate indicated by the AG and receives a Relative Rrant (RG) in the next Transmission Time Interval (TTI). Upon receipt of an AG with the second UE-ID, the UE does not receive an RG.