A method and apparatus provide a broadcast parameter message in a mobile communication system providing a broadcast service. If the provided broadcast service is time domain multiplex (TDM)-multiplexed, a message generator generates the broadcast parameter message by setting a field indicating the TDM multiplexing, setting a field indicating a position of the broadcast service in each sub-buffer, setting a field indicating whether one sub-buffer includes one service and a field indicating validity of the field, and setting a field exclusively indicating actual broadcast service data stored in one sub-buffer. A transmitter modulates the broadcast parameter message and provides the modulated broadcast parameter message to a terminal that receives the broadcast service.