Abstract：According to the interpretation marks of active faults and ring-shaped structures and the results of the field survey，about 200 faults and 26 ring-shaped structures were determined. Fault structures strike northwest，northeast，south-north and east-west，respectively；and the faults which strike northwest are regional faults and have controlled the development of geomorphology and river system in the project area. There are 22 faults whose linear features in remote sensing images are more obvious and scales are larger in all faults. Among them，8 regional or main faults have relatively larger effects on the stability of water transfer project. However，it has been stated clearly by synthetical analyses that，although 2 faults among 8 larger-scale faults have obvious active signs since Holecene，they don¢t pass through the water transfer route and even if the other 7 faults cut through the water transfer route，they don¢t have evident active marks since late Quaternary，so they don¢t have critical threat on project stability. It has also been shown that the project area lies in a relatively safe island through regional geological structural analysis. Most ring-shaped structures were formed by magmatism and can improve the project stability to some extent. Four dam areas including Ada，A¢an，Shangduke and Ya¢ertang dams are still in the structural stable period at present. In short，the project of the west route of South-to-North Water Transfer Project can be carried out.
