The purposes of this study were to determine the effects of lower extremity plyometric training on the proprioception and postural stability of collegiate soccer players with postural instability. The study was conducted from April 17, 2009 to September 28, 2009(fur a total of 6 weeks). Ten male collegiate soccer players were enrolled into the study, then divided into two groups: the plyometric training group(PMT) and the classical postural stability training group(CPT). P1yometric training on the lower extremities showed statistically significant improvement on proprioception and postural stability(p<.05). Although not all neurophysiologic mechanims underlying such an effect were revealed, it is proposed that plyometric training can be used as an effective training program to improve functional postural stability in soccer players with preexisting postural instability.