Object:To study the effect of Liuwei Dihuang (LW) decoction on stress induced imbalance of hypothalamus-pituitary-ovary (HPO) axis in female mice.Methods:Mice were subjected to hanging stress every day (30 min for the first 3 days

and after word increasing 30 min for every 3 days).The total-duration of stress was 25 days.Radioimmunoassay (RIA) was used to test the concentrations of hypothalamal Gonadotropinreleasing hormone (GnRH) and serum estradiol

and the western blot technique was used to quantify the level of luteinizing hormone (LH) in the pituitary.Results:The body weights of stress-loaded mice were markedly increased and the estrus cycle and the diestrus was significantly prolonged in stress-loaded mice.Meanwhile

the concentrations of hypothalamal GnRH and pituitary LH in stress-loaded mice were significantly decreased

while the levels of serum estradiol were significantly increased.Oral administration of LW showed little effect on the oestrus cycle in stressed mice

but showed significantly improving effects on the levels of hypothalamal GnRH and pituitary LH.The serum estradiol concentration of stressed mice was significantly restored after LW administration.Conclutions:Stressing mice by hanging induced malfunction of HPO axis

and LW improved or restored the disturbance of HPO axis in stess-loaded mice.