Abstract: Wireless multimedia sensor network (WMSN), as a multimedia information acquiring and processing technology, make potential applications span a wide spectrum from military to industrial fields. Research on wireless multimedia sensor network relates to many techniques. Medium access control (MAC) is at the core of effective communication. Owing to the energy constraints of the small, battery-powered sensor nodes, it is desirable that the medium access control protocol enable reliable, error-free data transfer with minimum retransmissions while supporting application-specific QoS requirements. There is some type of traffic with different QoS requirement in WMSN. Real-time traffic services demand low-latency. And, non-real-time traffic services demand high reliability. A different service medium access control (DSMAC) is presented for wireless multimedia sensor network. The four-channel protocol can support different service between real-time traffic using TDMA and non real-time traffic using contention based technology. It can support transmission of burst multimedia traffic through insert random contention period into frame. And a multi-channel inter-cluster transmission to avoid hidden terminal problem is proposed. Simulation analysis results and experimental results of difference-service, real-time, throughput, energy-efficiency, etc. show DSMAC is more suitable for wireless multimedia sensor network than other MAC protocols. Preliminary performance of DSMAC in real world system is discussed at the end.