Abstract:In order to explore the effects of different ecological management measures on soil carbon (C), nitrogen (N), phosphorus (P) content and their stoichiometry characteristics, thus to provide scientific evidence for ecological management and vegetation restoration of loess hilly region, by combining the means of field sampling and laboratory analysis, Wangmaogou which was the typical watershed in loess hilly region was taken as an example in this study, and the soil C, N and P contents and their stoichiometry of the 0—100 cm soil layer of 5 kinds of sample plots (sloping farmland, woodland, shrub land, grassland and terrace land) were analyzed. The results showed that: (1) Transformed into woodland, shrub land, grassland and terrace land by ecological management measures, soil C and N contents of sloping farmland respectively increased by 1.27, 1.18, 1.24, 1.14 times and 1.64, 1.64, 1.76, 1.57 times; There were significant positive correlation between soil C and N. The vertical distribution of the soil C and N in the 0—100 cm soil profile of woodland, grassland, shrub land and terrace land were quite consistent, showing the same trend of decreasing with soil depth and both appearing enrichment phenomenon in the 0—20 cm soil layer, while soil P did not change much with soil depth. (2) Soil C∶N mean value of sloping farmland was significantly higher than that of other plots (P<0.05), while the surface soil C∶P of sloping farmland was significantly lower than that of other plots (P<0.05). Soil C∶N did not change much, while soil C∶P and N∶P showed the trend of decreasing with soil depth. (3) The distribution of soil C, N and P stoichiometry was mainly determined by soil C and N. The correlations of soil C∶P, N∶P and ammonium nitrogen contents, soil clay contents, soil sand contents, soil water-stable aggregates were significant(P<0.05). Soil C, N, P contents and their stoichiometry were not only affected by ecological management and soil depth, but also were relevant to soil physical and chemical properties, meanwhile soil C∶N, C∶P and N∶P could indicate soil fertility level.