Abstract: To clarify the response mechanism of black kernel wheat to water stress, the field experiment method is used in this study. The black kernel wheat‘Shannong Purple Wheat 1’is taken as the material, two treatments (rainfed treatment and irrigation treatment) are set up. The accumulation and translocation of dry matter, grain filling characteristics and quality are studied. The results showed that under rain-fed condition, the peak value of grain filling formation rate appeared earlier, grain filling duration was shortened, and the average grain filling rate decreased obviously. Meanwhile, rainfed treatment increased the proportion of dry matter in grains at the mature stage, decreased the accumulation ability of dry matter after flowering and the total amount of dry matter, and reduced the ratio of dry matter in grains after flowering. Rainfed treatment mainly decreased the grain number per spike and 1000-grain weight of black kernel wheat, and obviously reduced the yield, while rainfed treatment did not affect the spike number per area significantly. Compared with irrigation treatment, protein content of grain, wet gluten content, gluten index, sedimentation value, dough formation time and stability time under rainfed treatment increased by 13.68%, 18.83%, 14.02%, 34.10%, 68.57% and 120.29% , respectively, the differences were significant. There was no obvious difference of soakage between the two treatments. Drought stress could decrease the yield by reducing the grain number per spike and 1000-seed weight of black kernel wheat, but it could improve the grain quality of black kernel wheat.