Urban social geography and its subfield--urban social-spatial differentiation have been developed since the 1960s. In China, with the development of urban geography during the 1970s and prosperity in the 1980s, its study fields have been expanded, the r~arch technology and theory have been renewed. There are two main sub-methodologies of urban social space study: ecological and comparative methodologies. Since Beijing, Shanghai, Guangzhou metropolitans are located at the window of China to overseas, it is reasonable to chose them as the main research regions, and the study on them has been strengthened since the 1980s. The research fields can be classified into five sub-fields: (1) social structure transformation and economic transit; (2) the change of cognition and behavior differentiation; (3) the relation between culture transformation and space differentiation in organization; (4) land use differentiation and the transit of planning' method; (5) material environment differentiation. We should strengthen the study of internal relation between resident space structure changing with time and space, and landuse; the division of a consumer and provision markets which can further understand the mechanism of social spatial differentiation; the effect of resident segregation; what's its benefits which can be accepted by community; and, how .to the study result of community replacement, state house distribution policy and management into the social practice.KEY WORDS: urban social space, progress in geography, social spatial differentiation, urban social geography Urban social geography and its subfield--urban social-spatial differentiation have been developed since the 1960s. Till now, by its basement and theory, it can be divided into three stages and four research schools. 1 ) methodological description stage; 2) behavior study stage; 3) radical Marxism stage which can be subdivided into two schools --structure and later structure study In China, with the development of urban geography during the 1970s and prosperity in the 1980s, its study fields have been expanded, the research technology and theory have been renewed. Recently, some new urban social problems have emerged, which make urban social geography earn much more space to fill the blanks of urban geography because of its structure defect and requirement for understanding the property of urban social problems, which strengthen the practice of research. Particularly, under the leadership of Premier Zhu Rongji, the government will take solving urban unemployment, housing and social welfare and so on as the main duties, thus renewing the study fields, methodology and the social practice (i) This project was ABSTRACf: Urban social geography and its subfield-urban social-spatial differentiation have been developed since the 1960s. In China, with the development of urban geography during the 1970s and prooperity in the 1980s, its study fields have been expanded, the research technology and theory have been renewed. There are two main sub-methodologies of urban so...