Pedospher is an important concentration center for pollutants including exhaust gases from vehicles, industrial wastes, the sedimentation of dust and suspended substances in the atmosphere, the combustion of coal and the sedimentation of other pollutants. The main soil contaminants include heavy metals, acid precipitation and organic components . Heavy metals are more considered due to irresolvable, high toxicity, carcinogenesis and cumulative effects. The purpose of this research was to determine the spatial distribution of As, Sb, Cu and Cr, calculate the geochemical background and contamination factor in surface soils of Hamadan province. Using Sb, Cu and Cr were fitted to the exponential model and As was fitted to the spherical model. The results of this study indicated that selected heavy metals have parent material origin and agricultural activities contributed to accumulation of As, Cu and Cr in agricultural land. Also study of spatial distribution of heavy metals showed that the highest concentration of heavy metals in the soils of studied region corresponds to sandstone, limestone, shale, metamorphic and igneous bed rocks. Key words : Heavy metals, Spatial distribution, Index of geochemical distribution, Contamination factor, Index of geoaccumulation, Hamadan.
