Objective:To study the influence of Sinapine on the formation of microvessels in chick embryo chorioallantoic membrane(CAM).Methods: Sinapine was purified by the procedure of pressurized-solvent extraction from Semen Sinapis Albae.The inhibition effect of Sinapine on the chorioallantoic vessel was detected by the chick embryo chorioallantoic membrane model.Results: Compared with physiological saline group,large areas of blood vessels in Sinapine groups(5.0g/L and 10.0g/L) had heavy inhibition of angiogenesis on CAM,accompanied by the decreased density of vessels(P0.05).Conclusions: Sinapine can prevent the formation of microvessels of CAM and the effects depend on the concentration.