This paper introduces social worker licensing system in different countries and reviews the development process of social work system in Taiwan, by which the author proposes an ideal model of the indigenous professional social work system and makes suggestions for the future development in accordance. In the trend of professionalization, different countries have established step by step their own professional social work systems. In Taiwan, national social work examination was first held according to The Professional Social Worker Act in 1997. Social worker licensing system is, in general, divided into two categories: examination and registration. The licensing system based on examination has come to the most mature stage in USA. Japan, Taiwan, while China also adopts the licensing system on examination. The licensing system based on registration has long been adopted by UK, Germany, and France. Hong Kong and Singapore also have their own well-designed and well-managed registration system. The developing process of social work system in Taiwan can be defined in five stages: the import from the western world, initiating stage, formation stage, legalization, the critical developing stage since 2007. The establishment and operation of the professional social work system in Taiwan can be conducted with a model constituted with eight aspects: education, examination, employment, continual training, professional organization, social consensus, professional culture, and internationalization, to all of which the author makes suggestions.