D-galactose (D-gal)-induced aging model is widely used in the study of the pharmacodynamics of antiaging drugs. The model has a shorter life-span, disorders in learning and memory, reduced immune function and other aging characteristics. Regular and quantitative injection of D-gal solution to rats can produce symptoms of natural aging models that are used in screening of antiaging drugs, and their pharmacological activities. This paper provides a summary of the mechanism of rat model induced with D-gal solution. The methods of building and evaluation of the aging models are provided. The theoretical basis is included to facilitate the subsequent research and experiment in the mechanism study of aging and antiaging medicines.