It is well recognized that M-cadherin plays important roles in myogenesis. In the present study we investigated M-cadherin expression in skeletal muscle in denervation/reinnervation process. After rat sciatic nerve was resected by fine scissors, the nerve was sutured using 10-0 monofilament nylon suture. At various periods up to 24 weeks after the operation, the rats were killed by cervical dislocation, and the gastrocnemius muscle was removed. M-cadherin expression in the muscle was detected by Western blot analysis using anti-M-cadherin monoclonal antibody. The level of M-cadherin expression in the muscle was calculated as the relative amount to that found in normal control muscle. The level of M-cadherin expression was significantly low at 1,2,4,6 postoperative weeks, but the level returned to the control level on 9th postoperative week. The minimum level of M-cadherin was 0.184±0.01 fold at 1st postoperative week. The operated foot started to move at the 6th postoperative week, and the degree increased with time. Theseresults demonstrated that the level of M-cadherin expression in skeletal muscle decreased in denervation/reinnervation process. Moreover, it may be suggested that expressed M-cadherin plays important roles in the functional regeneration of the skeletal muscle.