Abstract: Field experiments were conducted in Yangling District in a semi-humid area easy to drought, using wheat as an indication plant. During the spike forming to flowering stage of winter wheat. photosynthesis rate(Pn) and transpiration rate(Tr) were all determined for treatment with different cuitivated measures in order to study the effects of cultivated factors on leaf water use efficiency(WUE). The analysis of synthetic action of main cultivate factors(irrigation. nitrogen and density of crop planting) on WUE of winter wheat showed that the importarice of factors to WUE was in order of density, irrigation and nitrogen, low-density was more sensitive to WUE than that of supply nitrogen under limited water supply. The interaction among cultural pratices combination was obviously. Under low nitrogen conditions,irrigation and low-density stimulated WUE to increase, and the effect of low-density on WUE more than that of irrigation. The WUE decreases gradually with high-density. Irrigation and supply nitrogen may reduce the effect of high-density on WUE, but the promotion of irrigation on WUE was much stronger than that of supply fertilizer.