Mapping of soil background content in Beijing area is comprehensively and systematically presented in this paper. Basic data in mapping soil background content has 302 analytical data of soil elements and regional distribution which are mapped with computer plotting and factor analysis. The soil background content map is in statistic form and divided into grades; Criteria for dividing grades are parent rock in mountains and soil parent material and soil texture in plain area. Counties and districts are used as mapping units. Significant test is used by dividing grades of background content Maximum values of statistic error of background content in soil is mercury element in brown earth and cha soil, 18.4% and 12.9% respectively: All others are below 10%.