Abstract: Taken the grape cultivar ‘Shine Muscat’ as the material, the effect of the combination of GA₃ and CPPU on the lightresponse curves in the fruit adjacent leaves and fruit quality were investigated two weeks after blossoming. The results showed that nonrectangular hyperbolic model was more suitable for grape fruit adjacent leaf light response curve fitting. P_n and g_s of fruit adjacent leaves among all treatments increased with the increasing light intensity under the combination treatments of 25 mg·L^-1 GA₃ and 5, 10, 15, 20 mg·L^-1 CPPU, respectively, but C_i decreased. Fruit quality increased with the increasing CPPU concentration under the combination treatments of 25 mg·L^-1 GA₃ and 5, 10, 15 mg·L^-1 CPPU, respectively. Grape fruit adjacent leaf photosynthesis under the 25 mg·L^-1 GA₃ + 20 mg·L^-1 CPPU treatment was higher than  the other treatments. The fruit quality under the 25 mg·L^-1 GA₃ + 20 mg·L^-1 CPPU treatment was lower than  the 25 mg·L^-1 GA₃ + 15 mg·L^-1 CPPU treatment. It indicated that reasonable CPPU treatment concentration could improve fruit adjacent leaf photosynthetic ability and fruit quality. Too high concentration made the fruit quality lower instead. The 25 mg·L^-1 GA₃ +15 mg·L^-1 CPPU treatment was most appropriate in two weeks after blossoming.