【Objective】In recent years, the study on heavy metal pollution in soil has become popular. Although quite a number of scholars reported achievements in this field, they have not overcome the defects in regional background value and evaluation method, especially in salt lake basins in the arid region. So, it was difficult for them to achieve accurate results. The objective of this paper is to characterize spatial distribution and determine environmental background values of heavy metals pollutants, to evaluate soil quality using different methods, and to investigate sources of heavy metals pollution in salt lake basins, in an expectation to provide certain scientific reference for researchers in studies on accumulating basic data, determining environmental capacity, setting up soil environmental standards, protecting soil environment, eliminating soil environmental risks, rationalizing utilization of soil resources and so on and for government policy-makers in all these fields. 【Method】The Jilantai Salt Lake Basin, located in the arid region of Northwest China, was selected as the object for the study. Soil samples were collected from topsoil (0 to 10 cm), subsoil (50 cm) and substrate (100 cm) in the study area using the random arrangement method. Heavy metals (e.g. Cr, Hg and As) for analysis of chemical composition in the Inner Mongolia Key Laboratory of Water Resources Protection and Utilization. Spatial distribution of Cr, Hg and As was characterized through geo-statistical interpolation maps and background values of the elements in the soil environment were determined as benchmarks for evaluation of soil quality. Six commonly used methods (i.e. single factor index, geo-accumulation index, ecological risk index method, Nemero index, potential ecological risk integration index and pollution load index) were used to evaluate soil quality for comparison analysis. 【Result】Results show that the three heavy metal elements, Cr, Hg, and As, in the Jilantai Basin, were on the whole quite similar in spatial distribution characteristic; the background value of Cr, Hg and As in the soil of the basin was 27.89 mg•kg^-1, 0.039 mg•kg^-1and 12.83 mg•kg^-1, respectively; Cr was higher in the Bayinwula Mountain Region, the Wulanbuhe Desert Region, and the hilly southwestern part of the study area; Hg was higher only in the northeastern and the hilly southwestern parts of the study area; and As was higher areas near the lake, the Helan Mountain Region, the Bayinwula Mountain Region, and the Wulanbuhe Desert Region. The evaluation based on background value reveals that the three pollution elements in the topsoil of the study area followed a decreasing order of Hg > Cr > As in pollution level; the evaluation using the simple factor index method shows that Cr, Hg and As were all light in pollution level in the study area; the evaluation using the ecological risk method indicates that Hg was higher than Cr and As in ecological risk; and the evaluation using the comprehensive pollution index method suggests that the pollution of the three elements, when talked about separately, was slight in the topsoil, but their comprehensive ecological risk was high. The pollution level evaluated with the simple factor index methods was higher than that evaluated with the comprehensive pollution index method, Furthermore, the correlation coefficients of the evaluations using the two methods, simple and comprehensive, reached over 0.80 and 0.65 (a=0.01), respectively. In evaluating Hg, all the evaluations using the three comprehensive pollution index methods were significantly correlated with those using the three simple factor index methods, with correlation coefficient being 0.53 (a=0.01), while no significant correlations were found with the other two heavy metal elements.【Conclusion】It can be concluded from the spatial distribution characteristics and the evaluations that the presence of Cr, Hg and As in the surface soil of the salt lake basin is subject to the comprehensive impact of soil-forming parent material, natural hydro-geochemistry and climatic conditions, and partially to the disturbance of human activities.