A method of processing a multicast frame in a wireless local area network (WLAN) and an apparatus supporting the method are provided. The method comprises receiving, at a station, a unicast frame from an access point (AP), the unicast frame including an unicast address indicating a single station which receives the unicast frame, receiving a multicast frame from the AP, the multicast frame including a group address indicating a group of stations which receives the multicast frame, determining whether the unicast frame is duplicated with the multicast frame, and discarding the multicast frame if the unicast frame is duplicated with the multicast frame.