This study examined the effects of Korean red ginseng (RG) on muscle injury induced by eccentric exercise. Eighteen college male students were randomly assigned to either the RG group or the placebo group (P). The RG group ingested RG extract at 20 g/day (mixed with 200 mL of water) for 7 days prior to performing a downhill treadmill exercise and for 3 days after performing the downhill treadmill exercise, while the P group ingested 200 mL of water containing Agastachis Herba for 7 days prior to and 3 days following a downhill treadmill exercise. All subjects performed 2 bouts of a downhill treadmill exercise (6 km, -14 degree slope, 12 km/hr speed) with a 5 minute resting interval between bouts. Blood samples were drawn immediately before and after exercise, and at 1 hr, 24 hr, 48 hr, and 72 hr. Two-way repeated ANOVA documented that creatine kinase (CK) levels in the RG group were significantly reduced at 48 hr after exercise, as compared with P group, and remained constant until 72 hr after exercise. Lactate levels in the RG group were also significantly lower at 24 hr and 72 hr after exercise as compared to the P group. We conclude that supplementation of RGreduces CK levels and may prevent muscle injury induced by eccentric exercise.