Abstract: The belt of oasis border is usually called as ecotone of desert and oasis,which is mainly composed of shrub dunes.These shrub dunes can be divided into stable dune,semi-stable dune,semi-shift dune and shift dune by coverage of vegetation.A lot of studies have indicated that these shrub dunes are nature roughness unit and they have significant roles on airflow near land surface.They can change airflow structure and interchange of air torrent at boundary layer near land surface.They can also increase resistance of land surface to moving airflow by enhancing aerodynamic roughness length.When airflow blow passed shrub dunes,wind speed will be decreased remarkably because the dunes resist wind.So,shrub dunes in ecotone are very important defending barrier to nature oasis.This research selected a sample line(965m) mainly composed of stable dune,semi-stable dune and semi-shift dune in ecotone of Minqing oasis and one of stable shrub dune as study object.Field observation results indicate that mean wind speed at layers near land surface decrease 4.4% through the sample stable shrub dune and decrease 57% through the sample line.The mean wind velocity is reduced continuously along the sample line.At the edge of cropland inner of oasis,the wind velocity is only 21% referring to reference observation point. But shrub dunes in ecotone of oasis are one kind of the most vulnerable and unstable ecosystem and they are easily vulnerable to become degeneration ecosystem so as to threaten the sustainable development of oasis.The evolutions of shrub dunes are mainly influenced by human activities and climate changes.If they degenerate to be shift dunes,they will change from shelter barrier to be dust bowl.So,attention should be paid not only to the inner but also to the outer of oasis about its protection.Shrub and grass belts should be built in the surroundings while windbreak grid built in the inner and base windbreak built at the edge of oasis.Water is the most important factor to the stableness of the ecotone.It is significant for the sustainable development of oasis to supply sufficient ecological water utilized to realize the stableness of the belts of oasis border,at the same time,all kinds of human destruction activities should be forbidden.