A method and system or access point (AP) for performing a data transmission process supporting power management of wireless local area network (WLAN) clients comprises the steps of and means for performing the following functions, respectively: when data are received through a network, storing the data selectively, wherein the received data are not stored in a memory when a current operation timing is in a first timing interval, and the received data are stored in the memory when the current operation timing is in a second timing interval; generating a beacon frame after determining whether data to be transmitted to the WLAN clients are stored in the memory according to a beacon frame generation interval; transmitting the generated beacon frame to the WLAN clients every beacon interval; and, when the transmission of data stored in the memory during the second timing interval is requested from the WLAN clients, transmitting the appropriate data to the WLAN clients. As a result, power consumption by remote stations is minimized.