A method of processing a multicast frame in a wireless local area network system. The method includes transmitting a request message for requesting a Directed Multicast Service (DMS) in which at least one multicast frame is transmitted as at least one unicast frame by an Access Point (AP), receiving a response message from the AP in response to the request message, and receiving the at least one multicast frame from the AP, the at least one multicast frame being transmitted as the at least one unicast frame. The request message includes a DMS descriptor list field comprising a Transmission Class (TCLAS) element field and a Transmission Specification (TSPEC) element field. The TCLAS element field includes a requested multicast group address for the DMS. The TSPEC element field defines Quality of Service (QoS) expectations information for the DMS.