Abstract: 【Objective】Provide a scientific basis for research on forest ecosystem carbon storage and nutrient cycling, by analyzing the quantity, seasonal changes and components of litterfall in three typical forests at different successional stages in the Xinglong Mountain of Gansu Province, China. 【Method】By using a litter trap, the quantity, components(needles, broadleaves, branches, flowers, fruits, bark and unclassified litter)of litterfalls and their monthly dynamics were measured in two successional stages of coniferous and broadleaf mixed forest(Populus davidiana-Betula platyphylla-Picea wilosonii forest)to dark coniferous forest(Picea wilsonii-shrub forest and Picea wilsonii-Fargesia nitida-moss forest)from August 2011 to July 2015.【Result】Annual litterfall amount ranged from 5 534.48 kg/hm² to 7 951.25 kg/hm² for the three forest communities, with the order ranked as Populus davidiana-B. platyphylla-Picea wilosonii forest >Picea wilsonii-shrub forest >Picea wilsonii-F. nitida-moss forest. The litterfall amount of the coniferous and broadleaf mixed forest was remarkably higher than that of the dark coniferous forest. The annual litterfall amount decreased gradually along with forest succession. Leaves(44.91%), unclassified(20.53%), branches(15.86%)and fruits(14.74%)were the main components of litter in the Populus davidiana-B. platyphylla-Picea wilosonii forest; leaves(41.22%), unclassified(23.58%), branches(18.53%)and fruits(13.32%)were the main components of litter in the Picea wilsonii-shrub forest; and leaves(37.48%), unclassified(27.51%), and branches(22.35%)were the main components of litter in the Picea wilsonii-F. nitida-moss forest. In leaf litter, broadleaves were dominant for the coniferous and broadleaf mixed forest, while needles were dominant for the dark coniferous forest. In all three communities, the annual dynamics of litterfall showed double-peaked curve patterns, although the timing of the highest and lowest points were different. For the coniferous and broadleaf mixed forest, the highest and lowest points occurred in October and July, respectively. For the dark coniferous forest, the highest and lowest points occurred in April or May and August or September, respectively. A double-peaked curve also described the monthly dynamics of needle litter, where the high points occurred in April or May and October. A single-peaked curve described the monthly dynamic of broadleaves, unclassified litter, branches, fruits and flowers. The highest peak of broadleaves occurred in October, while those for unclassified liter, branches, and fruits occurred in April or May, and that for flowers occurred in May or June. There was no obvious pattern for bark litter.【Conclusion】There was an obvious effect of forest succession on the amount and composition of litter. As forest succession progressed from deciduous broadleaf forest to dark coniferous forest, the annual litterfall amount decreased gradually. The percentage of annual litterfall of broadleaves gradually decreased, while that of needles gradually increased.