In order to obtain the difference of vegetation growth on sand dunes under the influences of paved sandbag barrier and straw barrier,vegetation species number,average vegetation density,height and vegetation coverage of sand dunes in Ulan Buh desert were investigated for three continuous years by quadrat investigation method on dunes protected by sandbag and straw barriers and bare dunes.The specifications,setting location and setting time of the barriers were studied at the same time.The study results show that the longer setting time of the sandbag and straw sand barrier led to better vegetation growth status.With the increase of the setting time, vegetation species number and average height of the two sand barriers remained similar,but their average vegetation density and coverage increased;the average vegetation density reached above 35%,and the vegetation coverage achieved 36.8%and 33.0%,respectively.The positive effects of sand barriers on vegetation increased with the sizes of the barriers:3m×3mwas best,followed by 2m×2mand 1m×1m.The setting locations of sand barriers also mattered regarding the vegetation growth:the best setting location was bottom lee slope,followed by windward slope,middle lee slope location,and top slope.The two types of sand barriers studied showed no difference of the effects on the vegetation growth according to the analysis of variance(p=0.14),however,the two sand barriers were significantly better than the control(p<0.005).