Abstract: 【Objective】Using the balance relationship of multiple chemical elements in the ecological process,  we aimed to determine the similarities and differences of C, N, P content, and their ratios in the leaf-litter-soil system among different types of Fraxinus mandshurica plantations. In addition, we investigated possible relationships between different components of the same plantation type, and provided theoretical reference for mixed tree species selection, nutrient regulation, and fertilization methods to F. mandshurica plantations.【Method】We studied pure F. mandshurica plantation, Larix olgensis ×F. mandshurica mixed plantation, Picea koraiensis ×F. mandshurica mixed plantation, and Pinus koraiensis ×F. mandshurica mixed plantation that were planted 29 years ago on the natural forest strip clear cutting land in the Forest Cultivation Experiment Station of Northeast Forestry University; leaf-litter-soil samples were also taken back to the laboratory for analysis. Organic C, N, P content in the leaf-litter-soil system was measured. C, N and P content, as well as their ratios in the leaf-litter-soil system of the four types of F. mandshurica plantations were compared.【Result】N and P content in F. mandshuricab and L. olgensis leaves were significantly higher when compared with those of Picea koraiensis and Pinus koraiensis. N and P content in the litter of F. mandshurica plantation were significantly higher when compared with those in the litter of the three kinds of mixed plantations. C, N and P content in the soil differed significantly among the different plantation types. C content was the highest in L. olgensis ×F. mandshurica mixed plantation. N and P contents were the highest in pure Fraxinus mandshurica plantation. C, N and P content were the lowest in Pinus koraiensis ×F. mandshurica mixed plantation. The average decrease in the ratio of C, N and P content from leaf to litter, from litter to soil, and from leaf to soil in the four types of F. mandshurica plantations was 18.98%, 32.12% and 21.95%; 81.37%, 50.73% and 3.49%; and 84.90%, 66.55% and 24.67%, respectively. C/N and C/P ratios in F. mandshurica and L. olgensis leaves were significantly lower when compared with those in Picea koraiensis and Pinus koraiensis leaves; the N/P ratio in F. mandshurica leaves was significantly higher when compared with those in the three mixed plantations; C/N and C/P ratios in the litter of pure F. mandshurica plantation and F. mandshurica×L.olgensis mixed plantation were significantly lower when compared with those of Picea koraiensis×F. mandshurica and Pinus koraiensis ×F. mandshurica mixed plantations. The N/P ratio in the litter of pure F. mandshurica plantation was significantly higher when compared with those in the three mixed forests; C/N and C/P ratio in the soil of F. mandshurica ×L. olgensis mixed plantation was significantly higher when compared with those in the three mixed forests; The C/N ratio was the largest in the litter, but was the smallest in the soil in the four types of plantations. C/P and N/P ratios were the greatest in leaves, and the smallest in the soil among the four types of plantations.【Conclusion】This study aimed to examine ways to improve the efficacy of nutrient use, promote trees growth, and protect the soil. F. mandshurica and L. olgensis exhibited greater nutrient use efficiency and growth rate than that Picea koraiensis and Pinus koraiensis did; C, N and P content in the soil of pure F. mandshurica and L. olgensis ×F. mandshurica mixed plantations were higher than those in the soil of Picea koraiensis ×F. mandshurica mixed and Pinus koraiensis × F. mandshurica mixed plantation. Therefore, the most preferable mixed species should be L. olgensis. Based on C, N and P content, and their stoichiometric ratio in the leaf-litter-soil system of four types of F. mandshurica plantations, we propose that attention should be paid to soil N and P fertilizer application during F. mandshurica cultivation.