Abstract: The first 750kV transmission line in China locates in the transitional area of Tebit plateau and loess plateau, which have very complicated geological environment. In the paper the influence and the characteristics of such main geological problems as structural stability, landslide, mud-rock flow, ground fractures, excavation area and loess collapsibility are illustrated. Conclusions on corresponding research methods and how to solve the problems are drawn according to the real condition of the project.