Objective：By analyzing the distribution law of “zhongyun”，“sitian”and“zaiquan” of patients at birth，to discuss the correlation between the onset of breast cancer and the yun-qi endowment of patients，and to provide reference for preventing and treating breast cancer based on the “five yun and six qi” theory，namely the theory of five evolutive phases and six climatic factors in Chinese medicine.Methods：Collected 452 cases of female patients with breast cancer who were hospitalized and treated in department of galactophore surgery in the first affiliated hospital of Guangzhou university of Chinese medicine from November 2002 to August 2015.According to the year-counting method of“gan zhi”，also known as heavenly stems and earthly branches，statistically analyzed the data of distribution of“zhongyun”，“sitian”and“zaiquan”of patients at birth，discussed its relevance to the onset of breast cancer，and summarized the law of the yun-qi endowment in patients influencing the onset of breast cancer.Results：①There was correlation between the distribution of“zhongyun(tiangan)”of patients at birth and the incidence of breast cancer，among whom patients born in the“gui-year”，“ren-year”and“bing-year” accounted for a comparatively larger portion.②There was correlation between the distribution of the yun-qi model of“zhongyun(tiangan)-sitian-zaiquan” in patients at birth and the incidence of breast cancer，among whom patients with such yun-qi models as“bing-monarch fire of shaoyin-dry metal of yangming”，“ren-monarch fire of shaoyin-dry metal of yangming”，“wu-ministerial fire of shaoyin-wind wood of jueyin” and“geng-cold water of taiyang-damp earth of taiyin” appeared evidently more than others.Conclusion：There exists correlation between the onset of breast cancer and the yun-qi endowment of patients to some extent.The theory of five evolutive phases and six climatic factors can serve as a new method for predicting breast cancer.