Changes in snow water equivalent (SWE) over Northern Hemisphere (NH) landmasses are investigated for the early (2016-2035),middle (2046-2065) and late (2080-2099) 21st century using seven global climate models.These models form part of the Coupled Model Intercomparison Project Phase 5 (CMIP5).The results show that,relative to the 1986–2005 mean,the multi-model ensemble projects a significant decrease in SWE for most regions,particularly over the Tibetan Plateau and western North America,but a weak increase in eastern Siberia.Seasonal SWE projections show an overall decreasing trend,with the greatest reduction in spring,accompanying the rise in temperature.A stronger inverse partial correlation exists between mean annual SWE and temperature than between SWE and precipitation,and this relation is most significant in 21st century springtime.Moreover,zonal mean annual SWE exhibits significant reductions in three Representative Concentration Pathways(RCP),with the greatest decrease occurring at high latitudes (70-80°N).A stronger linear relationship between SWE and temperature at mid–high latitudes suggests the reduction in SWE there is related to rising temperature.However,the rate of reduction in SWE declines gradually during the 21st century,indicating that the temperature may reach a threshold value that decreases the rate of SWE reduction.A large reduction in zonal maximum SWE (ZMSWE) between 30° and 40°N is evident in all 21st century for the three RCPs,which attributes to terrain effects of Tibetan Plateau; while RCP8.5 alone indicates a further reduction at high latitudes in the late period of the century.This pattern implies that ZMSWE is affected not only by a terrain factor but also by the increasing temperature.In summary,our results show both a decreasing trend in SWE in the 21st and a decline in the rate of SWE reduction over the course of the 21st century despite rising temperatures.