With the aid of the Moran’s I index and GIS geostatistic interpolation methods, spatial autocorrelation and spatial distribution of organic carbon density (SOCD) in forest soils of Zhejiang Province were studied and effects of factors affecting SOCD were analyzed using the linear-regression equation. Results show that SOCD in the 0~30 cm layer of the forest soils of Zhejiang Province was 71.2 t hm^-2, on average, lower than the country’s. The overall Moran’s I of the SOCD in Zhejiang Province was 0.176, demonstrating significant spatial autocorrelation. SOCD in the forest soils of Zhejiang Province displayed in distribution a gradient declining from southwest to northeast and three parallel belts. Significantly positive relationships were found of SOCD with dominant tree species, slope position, slope aspect, age group, altitude, shrub coverage, shrubs average height and average age, and a significantly negative relationship was found with herb coverage. SOCD in the 0~30 cm soil layer was not much affected by herb average height. All these influencing factors explained 14.9% of the variation of SOCD.