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Drip irrigation is an important water-saving wheat cultivation technology, but little is known on its quality. The aims of this work were to investigate the grain quality under different irrigation amounts, and found out the optimum water condition for obtaining the best grain quality. The irrigation treatments consisted of two varieties (Xinchun6 and Xinchun22) and three water volumes (W1, 3,750 m(3) hm(-2) ; W2, 6,000 m(3) hm(-2) ; W3, 8,250 m(3) hm(-2)). The plots were irrigated every 10 days during the growing season. The result showed that W1 and W2 resulted in water stress to different degrees, manifesting 40 days and 60 days after wheat emergence, respectively. However, besides for sedimentation being less affected by moisture, W1 obtained the best results for other grain quality measures such as protein content, wet gluten content and starch gelatinization characteristics, whereas protein yield and farinograph parameters were optimized in W2. Therefore, for optimal growth of spring wheat in the arid and semi-arid areas of the in northwestern region of China, grain quality can be maintained if the drip irrigation volume does not exceed 6,000 m(3) hm(-2) during the entire growth period. The highest grain yield and relatively better grain quality could be achieved by maintaining soil water potential (SWP) at -61.67 kpa to -61 kpa at the 20 cm-40 cm soil layer 15 cm away from the drip irrigation belt after 40 days of wheat emergence and -39 kpa to -37.67 kpa at the 40 cm-60 cm soil layer. Although the SWP should be appropriately reduced after 60 days of emergence, values of approximately -82 kpa to -67 kpa at the 20 cm-40 cm soil layer and -54 kpa to -53 kpa at the 40 cm-60 cm soil layer should be maintained.