Under conditions of large-scale open-closed type rain-proof shelter, effects of regulated deficit irrigation (RDI) on grain yield and quality of winter wheat (Triticum aestivum L.) and their relationship were studied by the method of tubular soil cultivation, and the aim was to find suitable appropriate stages to impose RDI and degrees of water deficit, offering technical parameters to the establishment of RDI model with water-saving, high yield and good quality. A two-factor (RDI stages and the amount of water deficit) randomize block design was adopted in the pot experiment. Three water regulation deficit stages (beginning of spring growth (I), stem elongation (Ⅱ) and grain filling (Ⅲ)) were set up, and each stage included three levels of water deficit (60%~65%, 50%~55% and 40%~45% of the maximum field capacity for light, moderate and severe deficit, respectively). The results indicated that the grain protein content of winter wheat was not always negatively correlated with soil water content. There were differences in effects of RDI on grain protein content at different growing stages. The correlation between grain protein content and soil water moisture was negative at the stage Ⅱ. Light (60%~65%) or middle degree (50%~55%) of water deficit before jointing stage did not significantly reduce grain yield, protein yield and amino acid content, or even slightly increase grain yield, but severe degree (40%~45%) of water deficit would lead to significant yield reduction. However, even slight water deficit resulted in serious yields reduction after jointing stage. Light degree of water deficit at grain filling stage did not significantly decrease grain yield, but enhanced the water-saving effects and slightly increased amino acid yield. The results also showed that the correlation between grain yield and protein content was not always negative, which could be weakened or changed under certain conditions. There were significant differences in the relationship between grain yield and quality traits at different RDI stages Therefore, it was suggested that coordinating high grain yield in contradiction to good grain quality might be possible. The results of this study preliminarily confirmed that RDI was a practicable technique for coordinating relationship between grain yield and quality characters in winter wheat.