Abstract: Based on the concept of random contention and collision resolution, a QoS-based multiple access (QMA) protocol for Ad Hoc networks was proposed to support multimedia service and multi-hop architecture. The traffic was divided into two groups with different requirements on delay, namely real-time traffic and data (or non real-time) traffic. According to the protocol, nodes contend to access channel, and the node broadcasting the most forecast bursts (FBs) get right to access the channel according to its packet delay and the earliest deadline first (EDF) principle. Meanwhile, the nodes with real-time traffic have higher priority to access channel than those with data traffic by broadcasting FBs in earlier contention slots. Through simulations in OPNET modeler, it is shown that the QMA protocol outperforms the carrier sensing multiple access with collision avoidance (CSMA/CA) protocol in terms of throughput, message discard rate and average packet delay, and the QMA protocol can provide differentiated QoS guarantees for traffic in multi-hop networks.