Research methods: The summary is made for the different subsystem and different levels of transportations from general to concrete by adopting theory system of similarity and systematic analysis technology.
Research conclusions: According to the analysis，now the transportation similarity between Hainan and Taiwan is only 0. 4，but that will be 0. 805 after island-loop railway being formed. It shows the formation of island-loop railway is the key point to improve the overall service level of transportation so it is very necessary to build island-loop railway.
2007, Vol. 24 
