An improved pedodiversity methodology was applied for exploring the intrinsic relationship of the geo-spatial distribution patterns between the regional soil and surface water in a typical agricultural region of central China. Several parameters, such as the number of soil types, soil constituent diversity, soil spatial distribution diversity, and surface water spatial distribution diversity, were calculated and analyzed with 1 km grid scale. The results showed that the most representative soil groups in the study area were Ochri-Aquic Cambosol and Hapli-Ustic Argosol, and whose area in total accounted of 85% of the total area of the study region and their spatial distribution diversity were greater than 0.8. There was a data connection between the spatial distribution pattern of these two representative soil groups and the spatial distribution pattern of the regional surface water, the coefficient of determination (R²) was above 0.5, which was closely related to the role of water factor in soil-formation process of these two soil groups. The increase in the area of the study region would generally reduce the effect of surface water on the number of regional soil types. Compared with other soil-forming factors, the importance of the influence of water factor in soil formation was related to the size of study scale. The improved measurement methods and theories of pedodiversity which based on the discreteness analysis of the geo-spatial distribution of resources could provide a theoretical and data support for the evaluation of the spatial distribution pattern of different resource types (such as water and soil) and their interactive relationship.