A field experiment using litterbags was conducted in an alpine forest of western Sichuan in order to understand the effects of snow patches on the dynamics of N and P during decomposition of six representative species foliar litter in different periods of winter. Net N immobilization during foliar litter decomposition was observed in the whole snow cover season regardless of species. In contrast, P mainly released from foliar litter in the snow cover season, with a rapid rate of P release in the snow melt stage. Thick and moderate snow patches showed higher P release rates, but lower N release rates of foliar litter. The rate of N release was negatively related to daily mean temperature regardless of species, but the rate of P release was positively related to daily mean temperature with the exception of fir needle-litter. The decrease of snow cover in the scenario of global warming could inhibit P release but promote N release from foliar litter decomposition in winter in the alpine forest.