Disclosed herein are a method and apparatus for monitoring UE reachability in a wireless communication system. A method for monitoring UE reachability may include receiving, by a Mobility Management Entity, a monitoring request message for UE reachability including a maximum response time from a Home Subscriber Server, detecting, by the MME, the UE reachability if it is expected that paging is able to be transmitted to UE when extended Discontinuous Reception is applied to the UE, and sending, by the MME, a UE reachability notification to a Service Capability Exposure Function before a next paging occasion of the UE, wherein the maximum response time may indicate a time during which the UE maintains a reachable state so that downlink data is reliably delivered to the UE, and wherein an occasion when the UE reachability notification is transmitted may be determined by taking into consideration the maximum response time.