Wireless Full-duplex technique can significantly improve system throughput of a wireless network. Most existing full-duplex-supporting wireless MAC schemes only achieve symmetric transmission (i.e., the uplink throughput of a node is equal to its downlink throughput). However, in reality, the uplink and downlink traffic is often asymmetric. In this paper, we propose a novel MAC scheme called AT-MAC to achieve asymmetric transmission. In AT-MAC, upon receiving a packet, a receiver determines whether to execute a reverse transmission to the peer or to initiate a new transmission to a third node, according to the peer’s uplink and downlink requirements. Extensive simulations verify that the proposed design is feasible and efficient.