Wireless mesh network has been increasingly attracting attentions as enabling technology not only for access network to the Internet but for application oriented network. To strengthen reliability of wireless mesh network, adaptive loadbalanced routing to avoid congestion will be the key technology. This paper presents a novel concept of multipath routing with load balancing capability based on periodical packet distribution rate control. Packet distribution rate of each route adapts to delay cost calculated by using channel utilization of base stations on this route. Compared with existing load-balanced routing, the advantage of the proposed scheme is that it adapts to both sparse networks and dense networks. Results of performance evaluation by computer simulation demonstrate the advantages of the proposed scheme quantitatively. They show that it reduces average end-to-end delay by about 30% compared to loadbalanced singlepath routing scheme and simple multipath routing scheme.