Professionalization movement theory is a theory in profession sociology field to interpret the process of how a profession is formed，to find the attributions of a profession，and the regular pattern of its development. In this paper，professionalization movement theory is applied to measure the phenomena of social work as an emerging profession in Mainland China，after analyzing the experience of social work development in Guangzhou，Shanghai and Hong Kong，a sequencing of variables was made to compare the levels of professionalization in these cities，and also，their characteristics are summarized. In conclusion，it is founded that education performs as the main motive force of social work professionalization in China，but still shows shortage in several aspects：to find occupations，to cultivate profession organizations，to form a profession codes and ethics，to gain social sanctions，etc. And then，some suggestions and advices to social work education apartments were made accordingly to respond the need of professionalization of social work in China.