Abstract: Coarse Woody Debris (CWD) is an important component in forest ecosystems and provides important and unique ecological functions. Based on investigation to the storage amount and characteristics of CWD in sub-alpine dark conifer forests at upper reaches of the Yangtze river, this paper discussed the formation and sources of CWD in Abies fabri (Omei fir) forests at different age stages, and put forward a method of CWD classification by its constituents and decomposition grades. The result shows that the storage amount of CWD in over-matured Omei fir forest, matured Omei fir forest, middle-age Omei fir forest and Omei-fir with poplar mixed forest were 91.75, 71.72, 50.45 and 29.03 t/hm² respectively.