Abstract. This paper presents EARA-QoS an improved version of swarm-intelligence inspired ad-hoc routing algorithm EARA introduced in [11] . In this algorithm, we use the principle of swarm intelligence to evolutionary maintain routing information. The biological concept of stigmergy is used to reduce the amount of control traffic. A light-weight QoS scheme is proposed to provide service classification traffic control. The simulation results show that this novel routing algorithm performs well in a variety of network conditions.