Coarse roots(>5 mm) are important functional organs of plants. Its main physiological function is to maintain the growth of fine roots while transporting and absorbing water and nutrients from the soil. while it also stores photosynthates, anchoring and supporting the above-ground parts of the plant. Coarse roots are conduits for nutrients and water, as well as storage sites for carbon and nutrients. In addition, the turnover of coarse roots slowly transports carbon and nutrients to the soil and soil organisms and affects the long-term ecosystem productivity and CO₂ emissions of forests. Root decomposition is the main way that carbon and nutrients are returned to the soil. On average, the amount of underground litter in the forest accounts for about 48% of the total annual. Therefore, root decomposition is an important basis for the circulation of nutrients, carbon and energy within and between ecosystems, the biosphere and the atmosphere. Coarse root is important carbon pool and stock of nutrients in forest ecosystems, which plays an important role in the carbon and nutrient cycling of ecosystems. However, there are few studies on the dominant factors and decomposition patterns affecting the coarse root at present. In this study, the coarse roots (5-10 mm) of 10 tree species(Phellodendron amurense, Juglans mandshurica, Fraxinus mandschurica, Acer mono, Pinus koraiensis, Larix gmelinii, Betula platyphylla, Ulmus davidiana japonica, Tilia amurensis and Quercus mongolica)commonly found in the temperate forests of the Northeast China were studied by burier-bag method in 2020-2021, to explore the dynamic variation rule of the coarse root decomposition and release of nutrients. The results show that the annual decomposition coefficients of the coarse roots of Phellodendron amurense, Juglans mandshurica, Fraxinus mandschurica, Acer mono, Pinus koraiensis, Larix gmelinii, Betula platyphylla, Ulmus davidiana japonica, Tilia amurensis and Quercus mongolica are 0.826, 0.897, 0.477, 0.341, 0.358, 0.264, 0.244, 0.593, 0.458 and 0.227, respectively. The Juglans mandshurica decomposition rate is the fastest, while Quercus mongolica is the slowest. In the process of coarse root decomposition, different regulatory factors have different effects. The results prove that the decomposition rate of the coarse roots is negatively correlated with the initial C/N ratio of roots (P<0.0001) and initial lignin content (P<0.0001), but positive correlation with the initial non-structural carbohydrate content (P<0.0001). The initial C/N, lignin and non-structural carbohydrate content can explain 68%, 20%, and 65% of the coarse root decomposition rates across the 10 tree species, respectively. The conclusion is significance for predicting the carbon cycle and release of nutrients of coarse roots.