The crop populations of two different spring wheat genotypes (Kehan 19 and Longmai 33) were sprayed with 2% of urea, 5% of sucrose, and water at heading stage, respectively, to study the effects of exogenous carbon and nitrogen supply on formation and end-use quality of grain. The contents of amylopectin, amylose and protein fractions of grain, and gluten content and tensile property of dough were determined after grain harvest. Then, the protein quality and starch accumulation, and their relationship with end-use quality were analyzed. The results showed that, compared with the control, the contents of grain amylopectin and amylose of both cultivars were increased on average by 4.3% and 5.5% under the sucrose treatment, and by 5.3% and 8.6% under the urea treatment, respectively. Moreover, the sucrose treatment increased the albumin contents of Kehan 19 and Longmai 33 by 14.7% and 25.3%, and the prolamin contents by 10.2% and 8.1%, respectively; the urea treatment enhanced the glutelin contents by 5.0% and 7.3%, and the prolamin contents by 16.0% and 10.9%, respectively. However, the contents of insoluble protein in grains under the urea treatment were decreased by 26.3% and 44.5%, respectively for Kehan 19 and Longmai 33. Our results indicated that urea addition promoted the accumulation of gluten protein, and subsequently increased the content of wet gluten of flour and resistance of dough extension and energy, while sucrose addition improved the contents of starch and albumin in grains.