Objective:To investigate the effective mechanism of Huangning-Tablet for abnormal uterine hemorrhage caused by copper intrauterine device(Cu-IUD).Methods:Observing Huangning-Tablet-induced contraction activity of rat-uterine smooth muscles in comparison with that caused respectively by progesterone and oxytonin.Results:Huangning-Tablet can

to different extent

strengthen this contraction and it also has obvious resistance to the strong contraction brought about by oxytocin.Conclusion:Huangning-Tablet has dual-direction function of regulating the contractility of uterine smooth muscle

and consequently improves pathological state and exerts haemostatic function.