The effects of different acetic acid mass fractions 3%~9% and marination time (1~5 h) on the mass transfer components and quality changes of crisp grass carp (CGC) fillets during marination were analyzed. Kinetic model analysis showed that during acid marination at a mass fraction of 3%~9%, the changes in acetic acid, moisture, and mass exhibited good linear relationship with the square root of acid marination time. As acetic acid mass fraction increased from 3% to 9%, diffusion coefficient De value first increased and then decreased, reaching a maximum value of 6.11×10-9 m2/s at a mass fraction of 6%, indicating the largest driving force of mass transfer. Results of the theoretical study on mass transfer kinetics and measurements of the sensory and physicochemical qualities of CGC fillets identified optimal conditions for the acid marination of CGC fillets as 6% acetic acid mass fraction marinated for 1 h, which provided acetic acid, moisture, and water-soluble protein contents of 22.64, 740.30 and 466.75 mg•g-1, respectively, in CGC fillets. Conversely, mass change and water-holding capacity increased to 17.05% and 70.65%, respectively, total colony count decreased to 4.20 lg CFU/g, total sensory score was 55.12, and the fiber structure was relatively compact. In conclusion, marination with a 6% acetic acid mass fraction for 1 h improved the sensory and physicochemical qualities of CGC fillets and maintained a high mass transfer rate of acid marination liquid. These findings provide practical support and theoretical reference for the optimal control of food acid marination in actual production.