Abstract: In the research of fault tolerance parallel computer systems，routing algorithm is a very important subject.In this paper，the performance of 3-D Mesh networks adaptive routing and deterministic routing under the model in which each network node has independent failure probability is studied.Develope a new technique that enables us to derive formally proven success probability for the two routing schemes，so the routings can be compared and analyzed.The study shows that adaptive routing algorithm has the clear advantage over deterministic routing algorithm.On the one hand，the adaptive algorithm which is based on partial information becomes more effective.On the other hand，adaptive algorithm is more robust to node failure and to network size，so it has higher success probability.