Abstract: To study the effect of alkaloid constituents extracted from Yimucao Injection (YMCI) on uterine contractile activity,isolated uterus were prepared and treated by stachydrine,choline and trigonelline respectively or compatibilities between each two constituents at ratios of 2:1,1:1,1:2.Peak area (PA),frequency (Fre),mean contractile force (MCF) and amplitude (Amp) were monitored.The results showed that the 3×10^-5 mol/L stachydrine,choline and trigonelline and its two compatibility (1:1,2:1 and 1:2) had no obvious effect on uterine contractions in vitro of normal rats.But they can induce stimulate effects on the uterine contraction of the guinea pigs,which is mainly by increasing its shrinkage rate and at the same time reducing the frequency of contraction.Stachydrine,choline and trigonelline can have excitation on uterine activity,which is related to animal species,and there is no synergistic effect or antagonism on uterine.

Key words: stachydrine, choline, trigonelline, uterine, compatibility