The distribution characteristics of soil nutrients under different stand structures (in the 2-year-old poplar-crops agroforestry system) was studied. The results showed as follows. (1) The soil moisture content, pH value, organic matter, total nitrogen, total phosphorus, and potassium content at soil depths of 0-20 cm and 20-40 cm in poplar-crops agroforestry system had an obvious horizontal difference, but it was not obvious that the regularity of change of soil nutrients in different distances from poplar stem, which might be affected by the root distribution of poplar, soil microorganism, fertilization and soil tillage; In three poplar-crops agroforestry systems, soil moisture contents and pH values ??were higher than those of the control group; the total nitrogen content in the base of trunk was lower than that of the control group; total phosphorus and total potassium were not significantly different from those of the control group; (2) The difference of moisture content, pH, organic matter, total nitrogen, total phosphorus and total potassium content in four types of soil between the lower layer and the higher layer was highly significant (P<0.01). There were obvious vertical distribution, and the soil moisture content, pH, organic matter, total nitrogen content in upper soil in M₁ mode was higher, while the total phosphorus and total potassium contents in upper soil in M₁ mode were lower, which were opposite in M₂ and M₃ modes.