Abstract:In this study, a field experiment was conducted to investigate the effects of water-nitrogen coupling on the photosynthesis characteristics and soil water use of oil sunflower in a drip-irrigated multiple cropping system in the Shihezi region of Northern Xinjiang. Xinkuiza V, an early-maturing variety commonly cultivated in the region, was used in the two-factor (water and nitrogen) three-level completely randomized plot experiment. The oil sunflower was drip-irrigated. The results showed that the variation of topsoil water consumption of oil sunflower in a drip-irrigated multiple cropping system follow the growing process for anthesis> flower bud >grouting>seedling>maturity, anthesis and flower bud are two key water requirement periods, in particular, the anthes is the most sensitive stage to water; topsoil(0 to 40cm)water consumption increases with the increase of irrigation quota and the amount of nitrogen application; the water-nitrogen combination treatment of 3 000 m3 water per hm2 and 232 kg nitrogen per hm2 showed obvious coupling effect in the soil water use and yield. This study provides a scientific basis for the application of the high efficiency water and nitrogen optimization scheme and water and nitrogen efficient utilization of oil sunflower in drip-irrigated multiple cropping system.