Abstract： Polycystic ovary syndrome is one of the most common causes of menstrual disorders in women of childbearing age， which adversely affects the normal development of follicles and women's physical and mental health. Its incidence is increasing year by year， with a complex pathogenesis， long disease course and a transformation process from qi to blood. According to the view of “kidney being the root of innate endowment” and many years of clinical observation，polycystic ovary syndrome is always characterized by kidney deficiency being the origin and mostly deficiency in the origin and excess in the superficiality. Deficiency in the origin means kidney yin essence deficiency，kidney qi deficiency，kidney yin deficiency， and kidney yang deficiency； pathogen in the superficiality includes phlegm- damp， dampheat， and blood stasis. The pathogenesis evolution of polycystic ovary syndrome is explained in order to provide theoretical basis for its treatment.