The regenerating sciatic nerve of rat was teased into single nerve fibers at various intervals in 98 days after crushing. By image analysis, it was found that the values of architectural parameters of axon and myelin sheath, such as axonal diameter, myelin sheath thickess, their surface area and volume all increased apparently before 56 days, no any significant change was revealed between 56～98 days, and did not reach the level of each individual parent stump even upto 98 th day. In comparison of the architectural changes between axon and myelin sheath further, a parallel development in time course was demonstrated. The result not only indicated that a close relationship existed between axon and myelin sheath during regeneration, but also provided a further evidence that nerve regeneration was cooperated by the interation of both neuronal and nonneuronal regulators, which has been reported previously.