Phosphorus (P) released from foliar litter plays crucial roles in maintaining soil fertility and ecosystem productivity in the P-limited forest ecosystem. The present consensus is that litter quality manipulates the rate of P release during decomposition at the local scale, and climate runs the global-scale patterns in N release during decomposition. Recently, increasing evidences have been demonstrated that the process of litter decomposition is greatly affected by winter snow cover in cold biomes. As yet, the response of foliar litter P dynamics to snow cover gradient created by forest gap and crown canopy in the high-altitude forest remains unknown. In order to understand the effect of snowpacks on winter foliar litter P dynamics and the following process in cold biomes, therefore, the litterbags with fir (Abies faxoniana), birch (Betula albo-sinensis), larch (Larix mastersiana) and cypress (Sabina saltuaria) foliar litters were placed on the forest floor beneath different snowpacks created by forest gap and crown canopy in three alpine forest plots of eastern Qinghai-Tibet Plateau on October 26, 2010. The litterbags were taken back at the periods of onset freezing, deeply freezing and thawing in the non-growing season and in the growing season from December 2010 to December 2012, and the mass loss and P concentration in foliar litters were measured. P concentrations in foliar litters under the snow cover gradient enriched at onset period of freezing, thereafter released at deeply freezing period, and then enriched at the thawing period regardless of tree species. 30.04% to 42.59% and 8.00% to 18.04% of P were released from foliar litters in the first- and second-year of decomposition, respectively, and varied with tree species and snowpack depth. 10.15% to 30.01%, and 2.28% to 16.54% of P in foliar litters were released in first and second winter, respectively. Snowpack created by forest gap accelerated the P release of foliar litter, and higher rate of P release from foliar litters was observed under thicker snowpack. The effects of snow cover on P release from needle litters were more significant than that from broadleaved litter. Snow cover reduction slowed down the process of P release from foliar litters, which led to the difference of litter P release dynamics between in the growing season and in the non-growing season. These results imply that snow cover reduction caused by climate change and forest management might slow down the process of P release from foliar litters in high-altitude forest, and alter the P level in forest soil. More attentions should be given to the effects of heterogeneous environment factors on ecosystem process in the high-frigid forest ecosystem.