Research methods: Based on the experiences of planning and construction of urban mass transit networks in Nanjing and Guangzhou, the demonstrations are made for the necessity of planning, main contents，influencing factors and decision -making principle of laying track modes.
Research results: The analyses and comparisons of three modes of laying track in the ground, elevation and underground are made from the areas of applicable scope, land usage，environmental influence and construction cost for providing the technical support for laying track.
Research conclusions: The urban mass transit network plan is the important factor of guaranteeing construction of urban mass transit with scientificness , rationality, economic characters and operational characters, and the common sharing plan of line network resources can effectively guarantee the implement of line network plan of urban mass transit, which can provide the basis for design of the concrete project.
2007, Vol. 24 
