Abstract: Routing algorithm constitutes the primary factor influencing on the performance of massively parallel processors（MPP） system. The use of fully adaptive routing in an MPP interconnection network improves network performance by making use of all available paths and provides fault tolerance by allowing messages to be routed around failed channels and nodes. But it’s difficult to implement adaptive routing algorithm, and this limits its wide use in MPP systems, especially in commercial MPP systems. To reduce the implement complexity of adaptive routing algorithm and implement it simply and efficiently, the implement complexity problem in routing algorithm design is considered. By reducing the virtual channel requirements and imposing fewer restrictions on the choice of virtual channels, a deadlock free fully adaptive minimal wormhole routing algorithm LCFAA is presented, which needs very few virtual channels on every physical channel （3 n 1 virtual channels per router, not including the channels to or from the node） in n dimensional mesh. Compared with other proposed fully adaptive routing algorithms, LCFAA is fully adaptive with low cost, easy to implement, and scalable. Finally, the deadlock free property of LCFAA is proved, and its performance is demonstrated by simulation.