Research conclusions:(1)In addition to provide transportation services,the more important role of the suburban railway is to support the city population,resource,industry agglomeration and diffusion,guide and support the city layout and structure adjustment,promote city development.(2)Suburban railway emerged and developed before the subway,and the length of suburban railway line accounted for about 90% of the total length of city railways in Tokyo, Paris,London city. ( 3)The suburban railway should as far as possible pass through or into the downtown,linking up the subways. ( 4)The city public transportation system with the rail transit as the backbone lags in our country,and the suburban railway and Intercity railway more lag.(5)In many Chinese city,the planned rail network structure is not reasonable because some single metro line is too long and metro total amout is too large,but the planned suburban railway length is too small.(6)Chinese cities should learn from Paris and other cities of the world with special deference to Tokyo's experience,minimize the weaknesses,of suburban and intercity rail construction.