The present invention relates to a method and apparatus for controlling discontinuous reception (DRX) in a mobile communication system. The method for controlling the DRX of a terminal in a mobile communication system includes the steps of: receiving DRX-setting information from a base station; determining whether or not a first condition is satisfied, the first condition being that a current subframe exists between a first time point when receiving the DRX-setting information and a second time point when an event triggering the application of a short DRX cycle occurs; and applying a preset DRX cycle when the first condition is satisfied.