Aiming at three basic services,abnormal event alarm,information query and stream query service,the paper abstracts a QoS routing model for the multimedia sensor networks.Moreover,based on the traditional ant-based algorithm,we propose an ant-colony optimization based service aware routing (ASAR).The ASAR chooses the suitable paths to satisfy with the diverse QoS requirements from different kinds of service,thus maximizes network utilization and improves network performance.Finally,extensive simulation using NS2 is conducted to verify the effectiveness of our solution.Compared to the traditional ant-based algorithm,our ASAR algorithm has better convergence and significantly provides better QoS for multiple types of services in the multimedia sensor networks.