Abstract: In order to satisfy the requirement for the route location of the Shanghai-Hangzhou magnetic suspension project, a new form of geodetic coordinate system was proposed.This geodetic coordinate system is defined by meridians and parallel circles, but with two coordinate parameters expressed by length.As a result, the coordinate systems for the route location along with the whole line can be unified, and the precision of lengths and angles obtained from simple formulas based on the new form of geodetic coordinate system is very high and there is not any map projection distortion.The above conclusions have been proved by calculational results for the project.