Abstract: The Loess Plateau of north Shaanxi is a zone characterized by serious soil erosion,frequent natural disasters and fragile ecological environment.Nowadays,it is very important to undertake the divisional harness,dynamical monitoring and macroscopic regulation in the exploitation of resources,environmental protection and integrated realignment according to the comprehensive features and differences of the landscape ecological environment of this special area.Thus,Shenmu County,Fugu County and Hancheng City,the typical regions in the Loess Plateau of north Shaanxi,are selected to carry out the model experiment study of remote sensing evaluation on the landscape ecological environment.A comprehensive evaluation on the ecological environment quality in the typical regions is carried out by using the theory and methods of landscape ecology,taking remote sensing images as the basic information sources and combining the field investigation data.Because landscape itself possesses a high order and includes the surface organic plant communities and inorganic geomorphologic,hydrological, climatic,soil and other factors,it is a natural synthesis with regionalization.Remote sensing images can express the features and regional differences of landscape factors.In the paper,the function,structure and marks of landscape are analyzed,the environment quality of each unit is determinded,and the grade series are arranged.Which can provide a basis for divisional harness,expolitation and utilization of resources and environment monitoring in the typical regions,and also provide the available methods and technology for quantitative and quick evaluation,monitoring and regulation in a large scope in the Loess Plateau.

Key words: the Loess Plateau, ecological environment, remote sensing evaluation