Abstract: OBJECTIVE To discuss the effect of continuous illumination on reproductive endocrine and behavior of rats and intervention effect of Nourishing Yin and Tonifying Yang Fang sequential traditional Chinese medicine. METHODS Normal control group rats were under the light condition of 12/12 h light/dark cycle. Model group rats were under the light condition of 24h continuous illumination. Light intensity were chosen (300±20)lux. The time of building model was 50 days. The model assessment was according to the situation of estrus cycles. After eliminating unsuccessful models， residual model rats were randomly divided into model group and traditional Chinese medicine group. Control group and model group were given saline lavage. Traditional Chinese medicine group was given Nourishing Yin and Tonifying Yang Fang sequential traditional Chinese medicine treatment. Three groups of rats had forced swimming test and the sugar water preference experiments after the treatment. They were compared the fixed time and sugar water preference values. Three groups of rats were measured serum E₂(Estradiol)， FSH(Follicle Stimulating Hormone)， LH(Luteinizing Hormone)， GnRH(Gonadotropin-Releasing Hormone)， MT(Melatonin) and 5-HT(5-Hydroxy Tryptamine) after the treatment and compared between the three groups. The ovarian tissues of three groups， rats were observed under the electron microscope after the treatment. The difference of ovarian ultrastructure was compared among the three groups. RESULTS In the sugar water preference experiments， the sugar water preference values of the model group and the traditional Chinese medicine group were obviously lower than the control group. The sugar water preference values of the traditional Chinese medicine group rats were higher than the model group rats. In the forced swimming test， the fixed time of the model group and the traditional Chinese medicine group rats was higher than the control group rats. The fixed time of the traditional Chinese medicine group rats was lower than the model group rats. The level of E₂(Estradiol)， FSH(Follicle Stimulating Hormone)， LH(Luteinizing Hormone) and MT(Melatonin) of the model group and the traditional Chinese medicine group were lower than the control group. The level of FSH(Follicle Stimulating Hormone) and MT(Melatonin) of the traditional Chinese medicine group were obviously higher than the model group. However， there was no difference between the traditional Chinese medicine group and the model group on the level of E₂(Estradiol) and LH(Luteinizing Hormone). At the same time， the level of 5-HT(5-Hydroxy Tryptamine) of the model group was higher than the control group. The level of 5-HT(5-Hydroxy Tryptamine) of the traditional Chinese medicine group was significantly lower than the model group. However， there was no significant difference between the control group and the traditional Chinese medicine group. From the ultrastructure angle， there was visible damage in the model group and the traditional Chinese medicine group of ovarian cells compared with the control group. Furthermore， the injury of the model group was more serious than the traditional Chinese medicine group. CONCLUSION Continuous illumination may lead to mood disorders of rats， restraining the reproductive function and sex hormone level disorders. Nourishing Yin and Tonifying Yang Fang sequential traditional Chinese medicine can improve the mood and reproductive function of rats in a certain degree.