Sisheng Xinyuan is a work of academic excellence of HUANG Yuanyu,a famous medical doctor in the Qing dynasty,in which the identification and treatment of menstrual abdominal pain in Volume 10,Women''s Solutions,has a profound influence on later generations of medical doctors.In this paper,we use the'middle qi mediation'model to explain the pathogenesis of premenstrual abdominal pain as earth-dampness,water-cold,ethyl-wood depression,and blood-vessel congealment and astringency;and the pathogenesis of postmenstrual abdominal pain as blood-deficiency,liver-dryness,and wind-wood-impacted earth.Linggui Danshen Decoction is used to treat premenstrual abdominal pain,and Guidi Shaoyao Decoction is used to treat postmenstrual abdominal pain.Based on the above theories and clinical practice,the authors propose the treatment principle of combining cooling and warming with warming mainly,focusing on regulating spleen and earth to nourish kidney water,lowering stomach qi and clearing phasic fire for those who are hot,maintaining good mood to facilitate the smooth flow of qi,and reducing cold food for those who suffer from dysmenorrhoea,all of which reflect the guiding principle of'focusing on the middle qi'in HUANG Yuanyu's treatments.