Disclosed herein are a method for tracking area update in a wireless communication system and an apparatus therefor. Specifically, a method for user equipment (UE) to perform a tracking area update (TAU) procedure in a wireless communication system comprises: a step of transmitting a TAU request message to a mobility management entity (MME); and a step of receiving a TAU accept message from the MME, wherein if the UE uses signaling optimization to enable the delivery of user data through a control plane over the MME, and the UE does not have pending user data to be transmitted through a user plane and has pending user data to be transmitted through the control plane over the MME, then a first active flag can be set in the TAU request message.