The 62 observed points were made in Zhuanyaogou watershed in gully region of Loess Plateau. Spatial variability of soil organic carbon (SOC) content were analyzed by geostatistics approach. The complex factors affected spatial variability of SOC were preliminarily discussed. The results indicated that the SOC contents were very low in the studied watershed. The variability of SOC at different soil layer belonged to the middle intensity and was contributed to the influencing of the correlation rather than of the random. The SOC contents in the gullies were higher than those on the tops of the hills at the same soil layer. With the increasing of depth the SOC contents decreased and were higher obviously in the surface soil than those in the other layers. The change quantity of the profile SOC content on the tops of the hills were larger than that in the gullies. The possible factors of influence on the distribution of SOC were soil life, soil water content, soil and water loss and human activities.