OBJECTIVE Nerve conduit, a new way to repair peripheral nerve, has good prospect. Now, the main obstacle of the conduit's clinical using is the absence of material with both ideal physical property and good biocompatibility. In this study, the PLA is added to chitosan to form a novel material used to make a new nerve conduit. And the rat modal is used to get the data of the nerve conduit made of new material to repair the defect of peripheral nerve in vivo. METHODS Chitosan-PLA Composite Biodegradable material was used to produce a nerve conduit with depth of 200 um, diameter of 1.5 mm. This new conduit was used to repair the sciatic nerve's defect of 5 mm long. The other two groups as control groups repairs the same defects using silicon conduit or nerve's autograft respectively. 12 weeks after operation, normal assessments were performed including movement of hindlimb, hindlimb's retraction after being pricked by needle and ulcer in claw's palm. Special assessment was performed including histology, ECG, image analysis and weighing of triceps muscle of calf. The data of three groups was statistically analyzed by group t test. RESULTS As the normal observation showing: after 12 weeks, the regenerating nerve succeeded to path through the gap and dominated the muscle. Special assessment including ECG, image analysis and weighing of triceps muscle of calf showed that the group using Chitosan-PLA Composite conduit had the nervous regeneration better than silicon conduit group both in the nerve's quality and in axon's quantity. And the nervous regeneration of Chitosan-PLA Composite conduit group was as good as that of nervous autograft's group. CONCLUSIONS Chitosan-PLA Composite Biodegradable conduit could repair the defect of peripheral nerves successfully. It is an ideal material for nerve conduit.