Abstract: Litterfall is an important part of forest ecosystem and its decomposition process is the key processes of nutrient cycling in the forest ecosystem.Accurate determination of litter decomposition dynamics is very important for studying the pattern and process of forest ecosystems.Observations and determination were made of litter decomposition process of the Abies fabri forest in the Alpine Ecosystem Observation and Experiment Station at an altitude of 3 000 m over a long period of time.The results showed that (1) the decomposition rate of litterfall was listed in descending order:broadleaves > needles > twigs,and the time required to decompose the half of broadleaves,needles and twigs was 6.8 years,10.5 years and 14.5 years respectively;and the time to decompose 95% of them was 29.3years,45.6 years and 63.1 years,respectively.(2) Regardless of broadleaves,needles or twigs,the organic carbon content of them decreased with time,while the decomposition rate of organic carbon increased with time;By the exponential decay model,the decomposition coefficient of litterfall organic carbon was calculated and listed as:broadleaves > needles > twigs.(3) The organic carbon released by the annual decomposition of broadleaves,needles and twigs in Abies fabri forest was 52.18 kg·hm^-2,4.32 kg·hm^-2 and 0.67 kg·hm^-2,respectively.The total amount of organic carbon released by various litterfall was 61.13 kg·hm^-2 per year,accounting for 6.58% of the total organic carbon of litterfall.