Abstract: In the situation of implementing Yangtze River Delta integration development as national strategy, and new positioning of Chongming island as a worldclass ecological island, the engineering features, function orientation and construction requirements of the suburban railway Chongming Line in the third round of Shanghai rail transit construction planning are analyzed. The overall target for Chongming Line construction is put forward. Prospective route master plan is proposed for the development of higher quality and better level of regional transportation integration. The speed target, system format and operation organization mode of the line have been also analyzed and determined through comprehensive analysis, providing reference ideas for better future development of Chongming Line.