|（1.School of Physical Education，Jinlin University，Changchun 130012，China；2.Department of Physical Education，Shenzheng University，Shenzheng 518060，China）
Abstract: The aims of the study were to determine the structure change of drop-jump training and how it affect the lower joints and muscles when fatigued. Three-dimensional platform, Panasonic camera and MONARK 834E power-cycling was used to test 20 male athletes when unfatigued and fatigued. result indicated that the structure of the drop-jump is significant changed after fatigued. the center of gravity for the speed is Declined to reduce the flight distance, as well as access to significant increase in time, and other characteristics of declining knee function, changes in the scope of the knee point of view of the apparent increase, knee peak power significantly lower, the largest horizontal and vertical impact, Increased significantly, push the vertical stretch significantly less power. Biomechanics of these parameters change, we can see it not only significantly reduces the effect of jump training, while the muscles and joints increases the risk of injury.
Key words: exercise biomechanics；exercise-induced fatigue；drop-jump practice；plyometric training