In order to more comprehensively understand the alpine ecosystems structure and function under the background of global climate change,in situ soil incubations in three different snow depth(0,30,100 cm) and litter addition(0,5,20 g Sibiraea angustata leaf litter) were designed to measure the MBC content,MBN content and soil respiration in the eastern Tibetan Plateau. The research result demonstrated that more than 30 cm snow cover could effectively insulate soil and atmosphere, significantly reduce the amplitude and frequency of freeze-thawing cycle and significantly increase soil respiration. Litter input decreased microbial biomass nitrogen content,while increased soil respiration. The research results showed that snow cover and litter input(carbon input) in winter influence directly soil microbial activity which playing an important role in material cycle,and then upon the soil ecosystem processes in the alpine ecosystem.