Under the regulation of the hypothalamic pituitary ovary axis (HPOA), the related hormones in the female body present periodic dynamic change and physiological balance, which regulate menstrual cycle and other normal physiological activities through the influence on cyclical changes of the endometrium. This dynamic change and physiological balance mode is consistent with the theory of yin and yang in Traditional Chinese Medicine. The combination of the neuroendocrine system regulated by HPOA and the theory of yin and yang could promote the syndrome differentiation based on the general principle of yin and yang,and better guide for the clinical treatment of gynecological diseases.