Crop yields on the Loess Plateau of China are mainly limited by available water. A field experiment was conducted for winter wheat (Triticum aestivum L.) during 1995–98 to evaluate the effects of limited irrigation on crop yield and water use efficiency (WUE). The results showed that evapotranspiration, grain yield, biomass, WUE and harvest index depended on soil water content. The effect of irrigation on yield varied considerably due to differences in soil moisture content and irrigation scheduling between seasons. High moisture treatment gave the greatest evapotranspiration and biomass, but did not produce the highest grain yield and gave relatively low WUE. Appropriately controlled soil water content could improve grain yield, WUE and harvest index. Consistently high values of grain yield, WUE, and harvest index were obtained under conditions of mild water deficit at the seedling and start of regrowth to stem-elongation stages, with further soil drying at the physiological maturity to harvest stage. We therefore suggest that for winter wheat periods of mild soil drying in the early vegetative growth period together with severe soil drying in the maturity stage is an optimum limited-irrigation regime in this region