[Objective] In order to provide appropriate theoretical foundation for conservation of water and soil in southern red eroded soil region, the relationships between topography, land use and soil bulk density were analyzed in Zhuxi watershed.[Methods] The study was conducted in the area of Zhuxi watershed in Changting County, Fujian Province. Based on classical statistics and the geostatistics methods, the article analyzed the spatial variability of soil bulk density. The spherical model was selected as the best option for semivariogram. Ordinary Kriging interpolation was applied to predict the spatial distribution of bulk density. Zonal statistics function of ArcGIS was used to analysis the relationship between mean value of bulk density and elevation and slop, and raster overlay analysis was applied to calculate the area of bulk density in different land use types.[Results] ① The soil bulk density in watershed increased from northeast to southwest, and the lower bulk density area was located in west, and northwest and the higher bulk density area was located in southwest and central region. ② The bulk density decreased with the increase of elevation and slope, in contrast, slope position and slop aspect had little impact on spatial heterogeneity of bulk density in Zhuxi watershed. ③ Residential land and traffic land had a higher mean value of bulk density than the area covered by forests and grass.[Conclusion] Topography and land use were important factors which influence soil bulk density, while elevation and slope were regarded as the main terrain factors for spatial heterogeneity of bulk density in study area. There was a significant difference among different land use types, and the area with a good vegetation cover had a lower value of bulk density than other types. Therefore, to improve the soil structure in study area, vegetation conservation should be strengthened.