Soil organic carbon (SOC) and soil nitrogen (TN) are two important elements essential for vegetation growth, and meanwhile the major contributors of greenhouse gases, affecting the entire eco-environmental system. Accurate knowledge of how SOC and TN varies spatially and temporally and their driving factors at a regional scale is of some great significance to extrapolation of balanced fertilization based on soil C and N regulation as well as protection of the ecological environment. Therefore, based on the data gathered during the 2ndNational Soil Survey in 1981 and the measured data of 555 soil samples (0~20cm) collected in 2012, exploration was done of characteristics of the temporal and spatial evolution of organic carbon (SOC) and total nitrogen (TN) and it’s driving factors in the Purple Soil Hilly area of Mid-Sichuan Basin over the past 30 years. With the aid of GS+7.0 and ArcGIS9.3, spatial structure and spatial distribution of the two nutrient elements was analyzed. By means of classic statistics analysis, variance analysis(ANOVA) and regression analysis, comparison was performed of soil parent material, soil type, land use type, topography and vegetation in impact on spatial-temporal evolution of SOC and TN under different. The classical statistical analysis indicates that the mean content of SOC in the topsoil layer was 6.41g kg^-1 in 1981and 13.46 g kg^-1 in 2012, with coefficient of variation being 72.59% and 48.87%, respectively, and the mean content of TN was 0.88 g kg^-1 in 1981and 1.12 g kg^-1 in 2012, with coefficients of variation being 40.04% and 38.75%, respectively. Apparently, the mean content of SOC increased by 109.98% and the mean content of TN by 27.27%, while their coefficients of variation showed a decreasing trend, The spatial structure analysis reveals that over the past 30 years, SOC and TN was affected jointly by structural and random factors, but tended to be more affected by random factors. The ArcGIS9.3 interpolation shows that SOC and TN contents increased in most parts of the study area, especially in areas of low mountains and deep hills. The ANOVA demonstrates that parent material did not have much impact on SOC and TN contents(p>0.05); While soil type, topography, vegetation cover and land use did (p<0.001).The regression analysis indicates that land use type was becoming the dominant factor affecting spatio-temporal variation of SOC and TN, which implies that human cultivation is increasingly important in the spatial variation of both SOC and TN; while soil type was decreasing in its role but still cannot be overlooked as suggested in the structural analysis conducted here. The impact of topography was declining, while that of vegetation cover was rising over the past 30 years. The content of SOC and TN and the soil C/N was increasing, while the correlation coefficient of SOC and TN was decreasing slightly.