Purpose : The purpose of this study is to assess the effects of ice immersion to the ankle, foot on vertical jump, isokinetic exercise. Methods : Thirty volunteers from universal students who had not sustained an injury to the lower extremity within the past 6 months were randomly assigned to either an experimental or control group. Subjects in the experimental group performed vertical jump and isokinetic exercise before and after the application of a 15-minute ice immersion($50-55^{circ}F$) to the ankle and foot. Subjects in the control group performed vertical jump and isokinetic exercise before and after the application of a 15-minute resting. Results : Shuttle run was not significantly decreased after than before the application of a 15-minute ice immersion($50-55^{circ}F$) to the ankle and foot(p<0.05). Vertical jump was significantly decreased after than before the application of a 15-minute ice immersion($50-55^{circ}F$) to the ankle and foot(p<0.05). Speed $60^{circ}$ of peak torque was significantly decreased after than before the application of a 15-minute ice immersion($50-55^{circ}F$) to the ankle and foot(p<0.05). Speed $120^{circ}$ of peak torque was significantly decreased after than before the application of a 15-minute ice immersion($50-55^{circ}F$) to the ankle and foot(p<0.05). Conclusion : we think because the ice immersion decrease active, physical therapist should carefully consider the consequence of cold therapy to increase active.