Methods and apparatuses are provided for transmitting a status report by a receiving device including an automatic repeat request (ARQ) entity and a hybrid ARQ (HARQ) processor, in a mobile communication system. The method includes receiving, by the ARQ entity, a packet from a transmitting device through the HARQ processor; determining, by the ARQ entity, whether a status report is triggered based on at least one triggering condition; generating, by the ARQ entity, the status report including a reception status of the received packet at a transmission opportunity indicated by the HARQ processor, in response to the status report being triggered; and transmitting, by the HARQ processor, to the transmitting device, a packet including the status report.