Motivation is the critical drive of human beings behavior, and the certain level of motivation makes athletes achieve the best training effect. Based on that, the researchers investigate the situational motivation of 30 aerobics athletes inJiujiangUniversity. Shown as result, there are no significant differences on athletes of different genders in terms of intrinsic motivation, identified regulation and external principles. Males score slightly higher than females, but there are visible differences in terms of the loss of motivation, with female athletes losing more motivation. Significant disparity is shown on undergraduate aerobics athletes with different training years in the field of external principles and the loss of motivation. Training year increases as the score of external principles rise, and decreases as the score of lacking-of-motivation rises.