Abstract: Dynamic Source Routing（DSR） protocol is a typical route protocol for Ad hoc networks，its routing strategy is based on shortest path strategy instead of network traffic and the load of nodes，therefore the data flows tend to some of the links.The nodes on those links take on more network traffic，and they can form hot spots.The existence of the hot spots can shorten the lifetime of the network and also increase the average end-to-end delay of the packet，even affect packet delivery ratio.In order to solve the above problem，this paper proposes Load Based Dynamic Source Routing（LBDSR） protocol.LBDSR is an improved DSR protocol，and its routing strategy concerns the length and the busy degree of the route.It can effectively resolve the hot spot problem，decrease end to end delay of the packet，improve the network load balancing performance，and lengthen network lifetime.