Abstract: As an important node that directly links the rail transit system to the urban space，the railroad station gathers the resident population and the employment in the surrounding area of the railroad station ( referred to as the station area) to support the optimization of urban spatial structure． This study used Shanghai data to analyze the gathering level of residential population and employment in rail station areas at different ring layers of the city and classified rail station areas into 2 major types ( the employment type and the residential type) ，8 small classes based on job-housing density levels． Considering the urban activity center system planning，urban main center—urban sub-center—regional center，in“Shanghai Urban Master Plan ( 2016-2035) ”，the degree of support for urban central system was proposed based on the job-housing density of the railroad station areas and the spatial coupling relationship between the railroad station and the urban central system． It is concluded that the gathering level of employment and residential population to suburban railroad stations is still in its infancy and the average job-housing density of the railroad station areas at several levels of city center is significantly different: urban main center ( 43 thousand per square meter) ＞ urban sub-center ( 15 thousand per square meter) ＞ regional center ( 13 thousand per square meter) ． Besides，38 sub-centers and regional centers with low supporting degree that need attention in subsequent urban renewal were identified． This study will provide a reference for the sustainable development of railroad station areas in the urban sub-center and regional center of the suburbs，and for the rationalization of suburban job-housing spatial relationship．

Key words: railroad station area, job-housing density, spatial difference, urban central system, spatial coupling, degree of support to the center