Objective To analyze the changes in motor function during rat aging and explore whether treadmill training improves the age-related decrease of rat motor function.Methods 2-month-old, 8-month-old and 26-month-old SD rats were used in this study. The motor function parameters, including forelimb grip strength, endurance, rearing count and scurry speed were assessed before and after treadmill training for two weeks. Results 1)The forelimb grip strength, endurance, rearing count and scurry speed of the 26-month-old rats were significantly lower than those of the 2-month-old and 8-month-old rats.Moreover, the last three parameters were decreased with aging. 2) Treadmill training not only considerably improved the forelimb grip strength of 26-month-old and 8-month-old rats, but also increased the rearing count of 8-month-old and 2-month-old rats. 3) Treadmill training significantly increased the total scores of the motor function of 26-month-old rats.Conclusions The motor function parameters (forelimb grip strength, endurance, rearing count and scurry speed) of rats show an age-related decline. Importantly, treadmill training can improve the age-related decrease of total scores of the motor function. These four parameters can be used as aging parameters for motor function in rat models.