Abstract: Since the late Qing Dynasty and the early Republic of China，in the field of Chinese obstetrics，women's reproductive activities had gradually undergone a process of medicalization basing on the western medical knowledge，of which is a part of Chinese modernization.However，compared with the general debate between Chinese traditional medicine（TCM）and western medicine，the latter's predominance in the field of obstetrics and consequent establishment of a new medical order in it were less concerned by academia.Based on the analysis of historical archives about disciplinary practices of midwives in Beijing from 1912 to 1937，this paper discusses the strategies adopted by western-style doctors in competition with TCM doctors.It suggests that the success of western medicine in obstetrics during this time was more dependent on the interaction of many complex social and cultural factors than its advance knowledge and technology.