Disclosed are a method and apparatus for power saving mode-based operation in a wireless LAN. A method for power saving mode-based operation in a wireless LAN can comprise the steps of: an STA performing an initial configuration procedure for configuring a TIM-based power saving mode and an AP; the STA being converted from a doze state to an awake state, on the basis of a transmission period of a beacon frame, by operating in the TIM-based power saving mode on the basis of the initial configuration procedure, and thereby receiving a first downlink frame from the AP; the STA receiving from the AP operation mode configuration information indicating conversion from the TIM-based power saving mode to an active mode; and the STA receiving, on the basis of the active mode, a second downlink frame from the AP.