OBJECTIVE: To investigate the effect of olfactory ensheathing cells (OECs) on functional recovery after sciatic nerve injury. METHODS: Upon silicone-tubulization of transected sciatic nerve in 30 adult rats. Thirty rats were divided into two groups(SAL group and OECs group); saline and OECs were injected into the silicone chamber in SAL group and in OECs group respectively. The status of functional recovery of injured sciatic nerve was observed by electrophysiological analysis, axon morphometry analysis. RESULTS: In OECs group on the 30th and the 90th days after sciatic nerve transection: 1. The latent period of CMAP shortened by 0.60 ms and 0.56 ms; the nerve conduction velocity promoted by 6.42 m/s and 5.36 m/s; the amplitude enhanced by 3.92 mv and 5.84 mv, respectively; 2. The HRP positive cells in lateral nucleus of spinal anterior horn increased by 11.63% and 25.01%; 3. The number of nerve fibers increased by 1,047/mm2 and 1,422/mm2 and the thickness of myelim sheath increased by 0.43 micron and 0.63 micron, respectively. CONCLUSION: The olfactory ensheathing cells are capable of promoting the functional recovery after peripheral nerve injury.