Objective To explore the effects of electroacupuncture on brain derived neurotrophic factor (BDNF) of rats with sciatic nerve injury (SNI); To discuss its biological mechanism for treatment of SNI. Methods Fifty adult male Wistar rats were chosen, and the sciatic nerves of rats were cut off and pulled on both sides of the cut ends into nerve regeneration chamber. The rats were randomly divided into normal group, sham-operation group, model group, and electroacupuncture group. In the electroacupuncture group, the rats were treated by electroacupuncture for 28 days. After the treatment, the nerve regeneration was observed through HE staining. Immunofluorescence was used to analyze the expression changes of BDNF in the nerve tissue and spinal cord. ELISA was used to observe the changes of expression of serum BDNF. Results The amount of axon regeneration in the electroacupuncture group was obviously more than that in the model group, and the outline of the tissue more clear. Electroacupuncture could promote the expression of BDNF in the nerve, spinal cord and serum of SNI of rats compared with model group (P<0.01). Conclusion Electroacupuncture can promote the repairment and regeneration of SNI in rats by upregulating the expression of BDNF.