Disclosed is a method and apparatus for transmitting data by a terminal in a wireless communication system, the method including transmitting, to a base station, a scheduling request for requesting resources for transmitting a buffer status report, monitoring a control channel to receive resource allocation information, starting a timer for monitoring the control channel if the resource allocation information is received via the control channel, transmitting, to the base station, the buffer status report based on the resource allocation information, and stopping monitoring of the control channel if the timer is expired or a command is received from the base station.