To support scalability and efficient routing of ad hoc networks with movable nodes, many hierarchical and hybrid routing framework has been designed. At the same time, cooperation of ad hoc has been studied to improve the robust of wireless communication and save power. But the cooperation between nodes and routing regions is not considered. In this paper, we proposed a cooperative routing framework for ad hoc networks based on cluster agent. Cluster agent not only assists the routing query of node in cluster range, but also provides information needed for intra cluster routing. Based on cluster agents, useful information is efficiently managed and cached.