Abstract: The water use efficiency and transpiration rate of common tree species under different radiations were measured by using Li-6400 potable photosynthetic system in the excessive and thick sandland regions of Northern China. The results show that the order of the water use efficiency of 6 tree species is acacia＞haw＞poplar＞osier＞elm＞walnut, and also show that the water use efficiency of S.psammophilais greater than that of C. intermedia, but its transpiration efficiency is far less than that of C. intermedia and the drought-resistant ability of S. psammophila is stronger than that of C. intermedia.