[Background]Soil organic carbon (SOC) and soil total nitrogen (STN) are both important ecological factors in terrestrial ecosystems and important elements of global carbon and nitrogen cycle and climate change research.So far,there are many studies on the spatial distribution characteristics of soil carbon and nitrogen elements and their influencing factors in different scales or land use patterns at home and abroad.However,the methods are mostly based on ordinary Kriging and regression Kriging interpolation.There are few studies on the spatial distribution characteristics of soil carbon and nitrogen elements and their influencing factors based on the comprehensive effects of vegetation and topographic factors.[Methods] In order to study the spatial heterogeneity distribution of soil carbon and nitrogen elements in Dagangshan Watershed of Jiangxi province,the topsoil of the watershed was studied with ZY-3 remote sensing image as the basic data source.Based on ESRI ArcGIS 10.2 platform,NDVI and related terrain factors were extracted to establish the correlation model between SOC,STN and vegetation and topographic factors,so as to analyze the spatial distribution characteristics of soil carbon and nitrogen elements.In addition,topographic factors such as elevation,slope,terrain wetness index,water power index,and sediment transport index were selected to analyze their influence on SOC and STN spatial distribution.[Results] 1) The average contents of SOC and STN were 25.55 g/kg and 1.61 g/kg respectively,and the coefficients of variation were 64.16% and 28.37% respectively.Both SOC and STN were of moderate variation.2) Vegetation and topographic factors had a significant spatial correlation with SOC and STN,and the spatial distribution of SOC and STN were constructed based on NDVI,elevation,and terrain wetness index which showed SOC and STN decreased from northwest to southeast,which was consistent with the spatial distribution of NDVI and DEM.3) The contents of SOC and STN were significantly and negatively correlated with water power index and sediment transport index,but positively correlated with NDVI,elevation,slope,and terrain wetness index.[Conclusions] The above results prove that the spatial distribution of SOC and STN of the topsoil in the Dagangshan Watershed are determined by NDVI and terrain factors.The general trend of NDVI distribution in the distribution pattern of different vegetation types in the basin is gradually decreasing from northwest to southeast.At the same time,elevation,slope and TWI are decreasing from northwest to southeast,while WPI and STI are opposite.The above factors affect the spatial distribution pattern of SOC and STN in the watershed.The results may provide a reference for the spatial distribution of soil carbon and nitrogen in forest soil and the quantitative evaluation of soil and water conservation in the red soil region of southern China.