To explore effect of latitude on ecological stoichiometry characteristics of Robinia pseudoacaciaforest soil on the Loess Plateau, soil samples were collected from Robinia pseudoacacia forests in 13 counties distributed from south to north in Northern Shaanxi for analysis of soil C, N and P stoichiometry. Results show that (1) on sunny slopes, the ranges of soil C:N, C:P, N:P ratios varied in the range of 9.48~15.33, 8.93~59.79 and 0.77~5.11 respectively, in the 0~10cm soil layers and in the range of 9.13~13.57, 7.85~37.69 and 0.44~3.19, respectively, in the 10~20cm soil layer, while on shady slopes, they did in the range of 8.58~13.75, 9.46~47.71 and 0.76~3.63, respectively, in the top soil layers and in the range of 7.60~13.41, 5.99~31.28 and 0.54~2.65, respectively, in the 10~20cm soil layers. (2) Soil organic carbon and soil total N were quite consistent in spatial distribution, showing the same trend of declining exponentially with rising latitude and they were higher in the surface layers than in the subsurface layers, and the difference narrowed with rising latitude; Total P was lower than SOC and total N in spatial variability, showing a trend of rising first and then declining with latitude in the studied area. (3) Soil C:N ratio did not change much with latitude, while soil C:P and N:P ratios decreased significantly with rising latitude; and soil C:N:P ratio was higher in the topsoil layers than in the subsurface soil layer, but the difference was not significant.