Objective: To compare regeneration of motor fibers with that of sensory fibers by end to side neurorrhaphy and compare the effect of end to side neurorrhaphy with that of end to end neurorrhaphy. Methods: 20 SD rats were randomly divided into two groups: group A and group B. In group A, the right peroneal nerve was sectioned and the distal end was sutured laterally to the tibial nerve; in group B, the right peroneal nerve was sectioned and sutured with end to end neurorrhaphy. All left sides of two groups were used as control. Retrograde transportation of HRP was observed after 28 weeks. Results: The labelled neurons were also found in the anterior horn of the spinal cord and the spinal ganglia. Conclusion: The regenerative nerve fibers had motor fibers as well as sensory fibers by end to side neurorrhaphy. The effect of end to side neurorrhaphy is not as good as that of end to end neurorrhaphy. [