To explore the mechanism of acupuncture at Taichong(LR 3) on migraine rats with ascendant hyperactivity of liver yang.Methods:Fifty rats were randomly divided into blank control group(n=10) and model group(n=40).Rats in model group received modeling of migraine with ascendant hyperactivity of liver yang by gavage with Fuzi Decoction and subcutaneous injection of nitroglycerin.Thirty rats were successfully modeled and randomly divided into modeled group，LR 3 group and non-acupoint group，10 in each group.LR 3 group was treated with acunpuncture at bilateral LR 3 while non-acupoint group received acupuncture at bilateral subcostal non-acupoint both for 30 min.The behaviors of rats(ear redness duration and numbers of head scratching and cage climbing) were observed.The levels of calcitonin gene-related peptide(CGRP)，5-hydroxy tryptamine(5-HT)，and tumor necrosis factor-α(TNF-α) in serum were detected by enzyme linked immunosorbent assay(ELISA).Results:Ear redness appeared about 4 min after nitroglycerin injection and disappear after about 3 h in modeled，LR 3 and non-acupoint groups.Ear redness duration was shorter in LR 3 group compared with that in model and non-acupoint groups(both P<0.05).The numbers of head scratching and cage climbing of rats in model，LR 3 and non-acupoint groups were increased，but there was no significant difference between the groups before acupuncture(P>0.05).After acupuncture of 1 h and 2 h，the numbers of head scratching and cage climbing of rats in LR 3 group were reduced compared with those in model and non-acupoint groups(both P<0.01).Compared with the conditions in blank control group，the serum CGRP and TNF-α were up-regulated(P<0.05)，while 5-HT down-regulated(P<0.05) in the model group.LR 3 group group had lower serum CGRP and TNF-α(both P<0.05) and higher 5-HT(both P<0.05) than those in model and non-acupoint groups.Conclusion:Acupuncture at bilateral Taichong can significantly relieve migraine，and its mechanism may be related to the down-regulation of CGRP and TNF-α as well as the up-regulation of 5-HT in serum.