To discuss the mechanism of Pingganzhitong granules in the treatment of migraine and study its effect on the content of calcitonin gene-related peptide (CGRP) and 5-hydroxytryptamine (5-HT) in the plasma of rats with hyperactivity of liver-yang and migraine. Methods:The subcutaneous injection of nitroglycerin was performed to duplicate the rate model of experimental migraine. After the irrigation of Pingganzhitong granules, the enzyme-linked immunosorbent assay was employed to detect the content of CGRP and 5-HT in the plasma. Results:After the subcutaneous injection of nitroglycerin (NTG) in rat model of migraine, the content of CGRP in the plasma was significantly increased compared with the control group, while the content of 5-HT was increased to a certain higher extent compared with the control group. The dosage of Pingganzhitong granules with 24 g crude drugs /kg, 12 g crude drugs /kg and 6 g crude drugs /kg could significantly reduce the content of CGRP and 5-HT in the plasma of rat model of migraine. Conclusion:By regulating the content of vasoactive substances of CGRP and 5-HT, the Pingganzhitong granules can improve the abnormal vasodilation, inhibit the neurogenic inflammation and thus relieve the pain and achieve the treatment of migraine.