Objective: Using a self-developed chitosan with good biocompatibility to build artificial nerves to repair defects in rat's sciatic nerve and a study was made to confirm the repair effect.Methods: 30 healthy male Wistar rats were randomly divided into 3 groups(A: normal control group,B: in situ nerve graft group,C: Artificial neural bridge group).Sciatic nerve were cut off with the deal accordingly,12 weeks later,the nerve electrophysiological testing was performed.Results:12 weeks later,the nerve has been a long paragraph defect,the function of nerve conduction recovered.Conclusion: This casing can effectively bridge the Sciatic Nerve defect of 10mm in rats and can be used in the treatment of peripheral nerve defects.At the same time it can serve as a good carrier for the further development of tissue-engineered artificial nerves.