Objective To observe the morphologic changes of inferior alveolar nerve before and after osteocompression on dog′s mandible. Methods 8 dogs were selected and divided into 4 groups, 2 dogs per group. The osteocompressor was fixed on the right buccal side of the mandibule. Crew the compressor to compress the mandible 1.0 mm per 3 days for totally 15 days. On the 1st day, 15th day, 45th day and 90th day after osteocompression, the dogs of different groups were killed respectively. Get the inferior alveolar nerve and HE staining was carried on. Results ①On the 1st, 15th and 45th day after osteocompression, the fiber of the inferior alveolar nerve was obviously injured. ②On the 90th day after osteocompression, the injured nerve was almost recovered to normal. Conclusion The osteocompression could cause temporary injury on the inferior alveolar nerve, but the injury was reversible and might recovere by times after osteocompression.