[Objective] The spatial distribution and influencing factors of soil organic matter in Shaanxi Province were analyzed to reveal the relationships between soil organic matter and the influencing factors as topography, vegetation types, climate and other soil properties, to provide scientific basis for the study of soil carbon sink(carbon source) function change in this area.[Methods] Eighty-five top-soil samples were collected from 12 regional sites with different vegetation types and topographic conditions. Methods K-means clustering analysis and redundancy analysis(RDA) were used by SPSS 16.0 and Canoco 4.5.[Results] The soil organic matter concentration belonged to 2~6 levels, spatially having a decrease trend from the south to the north, and from the west to the east of province wide. The maximum value was 1.89~14.84 times of the minimum one. The contents of soil organic matter at different sample sites from a same region was not at similar level. Except for longitude and frost-free period, the content of organic matter was significantly affected by several environmental factors. Among which, years of vegetation restoration and vegetation types were the greatest influencing factors, slope gradient and aspect also have their influences and have obvious interaction effect.[Conclusion] Significant increase in soil organic matter content was found when farmland was transformed to other lands but orchard. The increase was more obvious with the increase of farmland converted ages, whereby it made reverted farmland shifted from carbon source to carbon sink.