Abstract: Objective:From the perspective of kinematics and dynamics, this paper investigates the increasing of leg inertia mass, namely weight-loading of lower limb on changing of sprint, explores the influence of training method on biomechanical characteristics of sprint, and provides theoretical guidance for sports training practice.Method:18male sprinters were recruited and required to sprint with different lower extremities loading conditions (0%, 10%, 15% of the leg mass) .The data was collected using high speed infrared motion capture system and force plates.Results:There were significant decreases in the ranges of motion of hip and ankle joints when the loads increased.15% of the leg mass loading made the joints torque and power decrease significantly, while the torque of knee significantly increased at the toe-off moment.In addition, the ankle absorbed more energy during the stance phase as well as the knee generated more energy during the swing phase.Conclusions:1) This training method might cause changes of elite sprinters' techniques.2) The changes of the joints torque and power attribute to the location of the loadings.The changes might happen to other joints if we change the location of the loadings.Training programs should be based on personal training purposes.