Abstract:Taking the natural desert steppe as CK, soil stoichiometry characteristics of artificial Caragana korshinskii shrubs with different density(HD, MD, LD) of the same forest age were investigated to reveal soil C, N, P balance and internal circulation in artificial shrub-grass ecological system. The results showed that with the increase of the density, soil organic carbon(SOC), total nitrogen(TN), total phosphorus(TP) and ratio of nitrogen to phosphorus(N/P) in 0-100 cm presented an increase trend, while the ratio of carbon to nitrogen(C/N) and carbon to phoshorus(C/P) presented a decrease trend, and the variation coefficient of TP was higher than other soil stoichiometry; Vertical direction SOC, C/N and C/P showed unimodal curve with the increase of soil depth, while TN, TP and N/P showed a sharply decrease trend in 0-40 cm soil layer with the increase of soil depth, but in 40-100 cm soil layer showed a slow decrease and tended to be stable. In 0-40 cm soil, TN and TP accounted for 61.82% and 55.56% of total content, and the content of TN and TP soil could be used as artificial C. microphylla shrubs sensitive index of soil nutrients; Correlation analysis showed that N content was positively linearly correlated with P content(p<0.01), and both was significantly negative correlated with C/N(p<0.01), and indicates consistent demand of N and P content in soil for C. microphylla shrubs.