Research conclusions:In the process of network planning，the decision on the laying mode of the urban rail transit＇s track，especially the track located in the peripheral regions，should be deeply researched according to the plan，the current situation and implementation conditions． The positions of building the transition section of Xi ＇an rail transit should be as follows: In the east city，the transition section should be built near the Chanhe River，in the south city，the transition section should be built in the south area to the Hantian Avenue and the West Avenue，in the west city，the transition section should be built in west area to the Third Ring Road，and in the north city，the transition section should be built in the area to Zhengzhou － Xi＇an High － speed Railway．