Embodiments of the present invention relate to the communications field, and provide a multicast sending apparatus, a multicast receiving apparatus, and a multicast transmission determining method. The method includes: sending at least one multicast frame to multiple stations in a multicast manner; generating a multicast indication request frame, where the multicast request indication frame includes an identifier of the at least one multicast frame, the multicast indication request frame is used to instruct the multiple stations to send an indication frame within a specified timeslot in a unicast and contention-based manner, and the indication frame includes an identifier of a to-be-retransmitted multicast frame; and sending the multicast indication request frame to the multiple stations in a multicast manner.