Objective To observe the changes of expressions of brain-derived neurotrophic factor (BDNF)and its receptor tyrosine kinase B(TrkB)and in rats with hemitransectional spinal cord injury(SCI)after electroacupuncture on Du Meridian and rehabilitation training.Methods The animal model of acute hemitransectional lesion at the right half of T11 spinal cord was established in 96 adult female rats,which were then divided randomly into an electroacupuncture group,a rehabilitation training group,an electroacupuncture combined with rehabilitation training group and a control group.All the groups received treatment on the 3rd d after operation.The electroacupuncture group and rehabilitation training group were given electroacupuncture on points of Du Meridian and rehabilitation training,respectively,and the combined group was given Du Meridian electroacupuncture in addition to rehabilitation training.Basso-Beattie-Bresnahan(BBB)scale was used to evaluate motor function every week.Twelve rats of each group were sacrificed 4 and 8 weeks after operation,respectively,and their spinal cord tissues were extracted.The polymerase chain reaction(PCR),reverse transcription-polymerase chain reaction(RT-PCR)and immunohistochemical techniques were used to detect the expressions of BDNF and TrkB.Results BBB grade increased gradually as time went on.There were significant differences between control group and other groups at the same time point(P ＜ 0.05).The scores increased obviously in electroacupuncture combined with rehabilitation training group compared with electroacupuncture group and rehabilitation training group(P ＜ 0.05).The result of immunohistochemical observation and RT-PCR also showed that there were significant differences of expressions of BDNF and TrkB among control group and other groups at the same time(P ＜ 0.05).The effects in electroacupuncture combined with rehabilitation training group were much more obvious than those in electroacupuncture group and rehabilitation training group(P ＜ 0.05),but there was no significant difference between electroacupuncture group and rehabilitation training group (P ＞ 0.05).Conclusions Electroacupuncture on Du Meridian combined with rehabilitation training had synergic effect on rat's SCI,and could obviously improve the restoration of rat's motor function; the mechanism maybe related to the upregulation of expressions of BDNF and TrkB.