Abstract: According to the theory of "six yang", Professor Xia Guicheng, a master of traditional Chinese medicine, pointed out that the key to the pathogenesis of endometriosis is "yang deficiency leading to stasis obstruction". On top of that, he considered that the treatment should not only promote blood circulation to remove blood stasis, and regulate menstruation to relieve pain, but also follow the female physiological cycle by using sequential therapy of regulating cycle. In conclusion, the particular attention must be paid to the transformation of yin and yang during intermenstruum and the continuation of extreme yang and the reaching of six yang during the premenstruum to maintain the dynamic balance of yin and yang in the patient's body, which provides a new idea for the treatment of endometriosis.