Litter decomposition is one of the important processes in forest ecosystem, which is controlled by both biotic and abiotic factors such as climate, litter quality, and soil organisms. Up to now, numerous studies have been made on the dynamics of aboveground litter in different forest ecosystems, nutrient release during its decomposition, and effects of biotic and abiotic factors on the decomposition, but less information has been reported on the decomposition of belowground forest litter. Recently, the responses of forest litter decomposition to global climate change characterized by elevated atmospheric CO2 concentration and temperature have got worldwide concern, but there remains uncertainty in research results. In the further study, more attention should be paid on the contribution of forest litter decomposition to soil organic carbon sequestration, the physical, chemical and biological processes of below- and above-ground litter decomposition, the responses of forest litter decomposition to the ecological factors (e.g. seasonal freeze-thaw cycle and drying-rewetting cycle) and their interactions, and the mechanisms of litter (especially belowground litter) decomposition responses to global climate change.