Due to its high flexibility, mobility and low cost features, wireless ad hoc network has been widely used in various applications. Security and quality of service (QoS) requirements are usually separately considered in such networks. Most of the existing routing protocols provide either secure or QoS routing mechanisms. Few protocols have combined these two requirements together. In this paper, we combine the security and QoS requirements together and develop a dynamic secure QoS routing protocol (DSQ), which simultaneously provides different levels of security and QoS service in the same network. The simulation results have demonstrated the effectiveness of the proposed protocol.