1. A method performed by a user equipment (UE) supporting an extended discontinuous reception (eDRX) in a wireless communication system, the method comprising:receiving, from a serving cell, system information informing that the serving cell does not support the eDRX;
transmitting a tracking area update (TAU) message to a mobility management entity (MME);
receiving a downlink message for a normal DRX cycle from the MME;
monitoring a paging signal in a radio resource control (RRC) idle mode based on the normal DRX cycle at the serving cell;
deprioritizing a cell reselection priority for the serving cell which does not support the eDRX;
performing cell reselection to another cell which supports the eDRX, based on the deprioritized cell reselection priority; and
monitoring a paging signal based on a eDRX cycle, which is longer than the normal DRX cycle, at the another cell.