What type vegetation should be chosen in the process of vegetation construction in arid and semi arid regions is an inevitable and often disputable topic. Five kinds of plant and two kinds of artificial windproof materials were used to observe on the difference of capacity of reducing wind velocity in windy days in the spring. Result shows that the order of these materials on reducing wind velocity is Artemisia ordosica>Achnatherum splendens>Hedysarum mongolicum andPycnostelma lateriflorm>grid sand obstacle>split rail>Salix matsudana. The ratio of wind velocity reduced by Artemisia ordosica is the biggest which reaches almost 50% and Salix matsudana is the smallest almost equal zero. As regard to the three life form type of windproof materials tree

shrub and grass

the order is shrub>grass>tree. By this

the conclusion that shrub and grass vegetation should take a preferential place in vegetation construction of arid and semi arid regions.