Abstract: Moisture is the key factor for the research and melioration of blown sand soil.The moisture of blown sand soil in the Shapotou region entirely comes from atmospheric precipitation.Shifting blown sand soil,with an unstable surface,is always in a conditon of deflation and accumulation.Its moisture content varies between 2%~3%,and withered coefficient amounts to 0.54%.Fixed blown sand soil tends to have an increasingly stable surface.Its black or brown crust with higher water capacity hinders water infiltration and replenishment into deep layer.Owing to plant evapotranspiration,its water condition is becoming worse,with a moisture content ranging from 1%~2% or less.Such a water change leads to the degradation of deep rooted plants and the invasion of annual plants as well as the succession of artificial ecosystem towards natural ecosystem.

Key words: Blown sand soil, Heat and water condition, Shapotou