The mixed-broadleaved Korean pine forest is a typical forest in Northeastern China, which plays an important role in maintaining the stability of regional ecosystem. The researches on litter decomposition of broad-leaved Korean pine forest can enrich the basic data and provide reference for nutrient cycling in this area. In this study, we selected 30 tree species and 16 leaf litter functional traits. Using litter bag method in the field and laboratory analysis we study the leaf litter decomposition rate of main tree species in the mixed-broadleaved Korean pine forest and the relationships between leaf litter decomposition rates and the leaf litter functional traits. The main results are as follows.After 365 days of decomposition, the mass loss of 30 tree species ranged from 20.56% to 92.11%. The mass loss rate of Pinus koraiensis is the lowest while the mass loss rate of Philadelphus schrenkii is the highest. For the different life form tree species, there were significant differences in the mass loss rate among different life forms, with shrub species having the highest mass loss rate and arbor species having the lowest mass loss rate. The fitting results of Olson model showed the decomposition coefficients (k) of 30 tree species ranged from 0.24 to 1.64, with Euonymus verrucosus having the highest k and Pinus koraiensis having the lowest k. The time required for 50% decomposition takes 0.43-2.86 years for different species and the time required for 95% decomposition takes 1.83-12.37 years. Correlation analysis showed that 12 of the 16 traits were significantly correlated with leaf litter decomposition. Among them, leaf thickness, leaf N content, leaf P content, lignin content, lignin:N, lignin:P had a strong correlation with litter decomposition rate. Therefore, the decomposition rate of litter can be predicted by some physical and chemical properties of litter leaves.