The nurse practitioner (NP) in Taiwan has officially become one of legal titles for the nurse from 2000. The first NP screening examination held in December, 2006, was divided into two groups include the internal medicine division and the surgical division, and the obstetrics & gynecology was under the surgical division. The screening examination of the Obstetrics & Gynecology NP rose from 2013 for the development of specialization in Taiwan, but the obstetrics & gynecology NP in USA has been developed almost 60 years. Hence, we could refer to the context and route of her obstetrics & gynecology NP development. This article introduces the developments of obstetrics & gynecology NP in Taiwan and USA, to understand more about the obstetrics & gynecology NP in Taiwan, and to train the professional NP. Finally, the clinical professional competence that the NP owns is also discussed in order to benefit the development of NP in the future.