The paper builds the multi-subject spatial database and the numerical analytical method because regional difference of Chinese ecological environment background is prominent. The ecological environment background condition is synthetically appraised and the index is used to reflect the general characteristics and the regional difference by the 9 kinds of spatial raster database i.e.precipitation

accumulative temperature

temperature

slope

aspect

elevation

NDVI

the building of the national appraisal index system of ecological environment background and the combined function of the GIS. The ecological environment index in divided into 10 grades. The higher the grade

the better the ecological environment is. The results will be beneficial to compare the regional difference of the ecological environment and to study the dynamic change in time series since it reflects objectively the natural characteristics and regional difference of China. The average index of Chinese ecological environment is 5 726. The ecological environment index increases and represents the better condition from Northwest to Southeast. Using the index

the numerical method is built to reflect the ecological environment background and to compare the regional ecological environment background that builds the foundation for future dynamic monitoring. The feature value of the subject index of every cell by the GRID module of ARC/INFO can be calculated to analyze the regional law and dynamic change and to study the main factors that have the effect on the background. The ancillary information can be supplied to help make decision on the resource exploitation and environmental protection pertinently and simultaneously by overlaying the data with the especially spatial data such as land use data.