Research methods: The comparison and research are done on the aspects of communication network technology，system constitution for Guangzhou Metro Line 2 accoding to the operational requirements and the development of communication technology.
Research results: The technological choices and network constitution are put forward, which can largely reduce the investment in communications system.
Research conclusions: The study should be done on the problems in designing the communication system when designing a new Metro line. The proposals are made that the skilled and experience integrator should be hired to control the whole construction process of communication system, the UPS of two hours should be equipped to the transmission system， wireless system, telephone system and main clock in control center and LIPS of one hour to the other systems, the main optical cables from car depot to the ground should be laid down in cable pipe and the pipe quantity should meet the long-term requirement, and the rainage system should be installed in rainy area for the manhole, which should be connected with the main drainage system of car depot to solve the problem of ponding in manhole.
2007, Vol. 24 
