Abstract: Taking two winter wheat (Triticum aestivum L.) cultivars (Gaocheng 8901 and Jimai 20) with high quality strong gluten as test materials, a 2-year field experiment was conducted to study the grain glutenin macropolymer (GMP)’s content and size distribution, grain quality, and grain yield under effects of different irrigation schemes. The schemes included no irrigation in whole growth period (W₀), irrigation once at jointing stage (W₁), irrigation two times at wintering and jointing stages (W₂), respectively, and irrigation three times at wintering, jointing, and filling stages (W₃), respectively, with the irrigation amount in each time being 675 m³·hm^-2. Among the test irrigation schemes, W₂ had the best effects on the dough development time, dough stability time, loaf volume, grain yield, GMP content, weighted average surface area of particle D_3,2, weighted average volume of particle D_4,3, and volume percent and surface area percent of particle size >100 μm of the two cultivars. The dough development time, dough stability time, and loaf volume were negatively correlated with the volume percent of GMP particle size <10 μm and 10-100 μm, while positively correlated with the volume percent of GMP particle size >100 μm, D_3,2, and D_4,3. It was suggested that both water deficit and water excess had detrimental effects on the grain yield and grain quality, and irrigation level could affect the wheat grain quality through altering GMP particle size distribution.