Objective To explore the changes of calcitonin gene-related peptide (CGRP) and substance P (SP) levels after end-toend and end-to-side neurorrhaphy. Methods Twenty female Wistar rats were divided into 4 experimental groups and control group. In the experimental groups, common peroneal nerves were transected on both sides. End-to-side coaptation was performed on the left, while end-to-end coaptation on the right. After 1, 2, 4 and 27 weeks, the rats were sacrificed, and immunoreactivities of CGRP and SP in suture sites, lumbar spine and dorsal root ganglia(DRGs) were evaluated respectively. Results The expression ofCGRP and SP decreased in dorsal horn and DRGs within 1 week postoperatively. After 4 -27 weeks, CGRP and SP in dorsal horn could return to almost normal level, but they had little recovery in DRGs. Although the trend of change between end-to-end and end-to-side was coincident, in most experimental groups, thereexisted differences in the dorsal horn between end-to-end and end-to-side. The sciatic nerve stained by acetylcholinesterase, SP, CGRP and PGP 9.5 showed that the fibers could pass through the suture site of either end-to-end or end-to-side. Conclusion Nerve regeneration can be achieved by end-to-side neurorrhaphy, andthe mechanism of sensory nerve recovery of these two methods is similar. But the recovery in end-to-side coaptation is insufficient to some degree.