Abstract:Geostatistics has proven to be useful for characterizing and mapping spatial variability of soil properties.In this paper,a geostatistics method,combined with Geographic Information System(GIS),was applied to analyze the spatial variability of soil organic matter(SOM) in topsoil in the typical granite red soil region of Southern China.The results showed that the mean of SOM was 2.73%,and the variance coefficients of that was 72.73%,which belongs to medium spatial variability.The theoretical semi-variogram model of SOM was spherical model.The C0/(C0+C) of SOM was 47.13%.It was also indicated that the SOM had obvious spatial self-relativity in this area,and the effective range was 21.48 km.The Kriging spatial interpolation showed that SOM decreased gradually from outside to central in the study area.There was the lowest value of SOM existing in the central area,and the highest value of SOM existing in the western area.The research findings can provide reference to ecological restoration and reconstruction in soil and water conservation region of the typical granite red soil region of Southern China.