Nitrogen is one of the most limiting elements for plants in alpine and high latitude areas which are covered by snow in winter for a long period. The mineralization of soil nitrogen under snow cover is a major component in annual nitrogen circle of soil. And climate change will have an important influence on soil nitrogen dynamics in winter by changing biogeochemical cycle and snow regime. However, so far, little work has been done on the eastern Tibetan Plateau. The effects of snow depth and duration of snow cover on soil N content and net N dynamics were explored by in situ PVC culture tubes method in the alpine belt of the eastern Tibetan Plateau from November 2010 to April 2011. 9 treatments (different snow depth and snow duration) were set by artificially to determine the inorganic N content (NH_4~+-N and NO_3~--N) and calculate net N mineralization. The results showed that snow duration had a significant impact on soil temperature.. Soil water content increased with the increase of snow depth and snow duration.NH_4~+-N is the main, accounting for 69%~86% of the soil inorganic N, while NO_3-N accounting for only 14%~31%. Deeper snow-cover (100 cm and 50 cm snow cover) reduced soil NH_4~+-N concentration, whereas did not change net N mineralization rate. No differences in soil N pools was found under the different duration of snow cover (60 d, 90 d, 150 d), showing that accumulation and release in soil N pools were not significantly changed by earlier continuous snow cover, although higher temperature and less freeze-thaw cycles were found.