Stocking and structural composition of a decidu-ous broad-leaved forest were determined to predict coarse woody debris quantity by quantifying the empirical rela-tionships between these two attributes. The most ecologi-cally significant families by stem density were Salicaceae, Betulaceae, Fagaceae, and Aceraceae. Populus davidiana was the most dominant species followed by Betula dahu-rica, Quercus mongolica, and Acer mono. The four species accounted for 69.5％ of total stems. Numerous small-diam-eter species characterized the coarse woody debris show-ing a reversed J-shaped distribution. The coarse debris of P. davidiana, B. dahurica, and Q. mongolica mainly comprised the 10–20 cm size class, whereas A. mono debris was mainly in the 5–10 cm size class. The spatial patterns of different size classes of coarse woody debris were analyzed using the g-function to determine the size of the tree at its death. The results indicate that the spatial patterns at the 0–50 m scale shifted gradually from an aggregated to a random pattern. For some species, the larger coarse debris might change from an aggregated to a random distribution more easily. Given the importance of coarse woody debris in for-est ecosystems, its composition and patterns can improve understanding of community structure and dynamics. The aggregation pattern might be due to density dependence and self-thinning effects, as well as by succession and mortality. The four dominant species across the different size classes showed distinct aggregated distribution features at different spatial scales. This suggests a correlation between the domi-nant species population, size class, and aggregated distribu-tion of coarse woody debris.