Carbon (C) and nitrogen (N) play important roles in plant growth and physiological functions. Study of the relationship between the C and N content in leaves of a plant and its environmental factors contributes to elucidating the supply of plant nutrients and plant growth in different environments which is of great significance to understand the distribution pattern of forest ecosystems and the trend of future changes,and even the response of plants to global change. This paper took the leaves of Picea schrenkiana(Schrenk's spruce) forests and the corresponding soil of the trees as the study objects. With samples collected from the field,we retrieved the C and N contents in the leaves and analyzed different soil layers. Then we evaluated the variation of C and N stoichiometric characteristics through statistical analysis. Finally, the redundancy analysis(RDA) was used to investigate the relationships between the stoichiometric characteristics of C and N from the leaves and the soil physicochemical factors. The results showed that the average concentrations of C and N in the leaf were 465. 28 g·kg ~(- 1) and 6. 54 g·kg ~(- 1) respectively, and the variation coefficient were 14% and 82% respectively. The RDA showed that in the soil layer from 0 to 30 cm the stoichiometric characteristics of C and N in the leaf were mainly affected by soil water content and its acidity- alkalinity. For the soil water content, there was a positive correlation with the C/N ratio but a negative correlation with the C and N content in the leaf while for the acidity-alkalinity of the soil, there was a positive correlation with C and N contents in the leaf but a negative correlation with the C/N ratio. In the soil layer from 30 to 80 cm, the stoichiometric characteristics of C and N in the leaf were mainly affected by soil water content and soil clay content. Specifically, for soil water content, there was a positive correlation with the C/N ratio. For soil clay content, there was a positive correlation with C and N contents but a negative correlation with the C/N ratio. Additionally, there were not significant relationships between pH and the C and N contents in the soil and the leaf's C and N stoichiometric characteristics. The soil water content in different soil layers was related to the stoichiometric characteristics of C and N from the leaf,which indicated that the soil water content had certain effects on nutrient uptake by plants,and that was not related to the soil depth.