PURPOSE: The purpose of this study was to determine effects of pre-season, high-intensity winter training on fatigue substances (lactic acid, ammonia), muscle injury marker (LDH, CK), and inflammation marker (CPK, CRP) in male judo players. METHODS: This study was performed with low-intensity training for 60 minutes once a day, uniform training for 120 minutes, and high-intensity training for 90 minutes once a day, weight training with resistance exercise for 90 minutes, another uniform training for 150 minutes, pulling the tube elasticity exercise for 60 minutes, and etc. ten male judo professional players with 5 years or greater of Judo experience, which of them was one of the winners of national-wide championship. RESULTS: There was no difference in lactic acid after low- and high-intensity exerecise, but ammonia significantly decreased (p<.05) after high intensity exercise. LDH significantly increased (p<.05) after the high intensive training. but CK significantly decrease (p<.05) after the training. CPK did not change after the low- and high-intensity exercises. but CRP significantly decrease (p<.05) after the low-intensity exercise, but it remained unchanged after the high-intensity exercise. CONCLUSIONS: It is speculative that muscle injury may occur due to accumulation of fatigue if the high-intensity training is continuously performed without an enough break or/and nutritional intake. It can be thought that the decrease of physical defense function may cause inflammation. Therefore, it is needed to study correlations between fatigue substances and related electrolytes. Additionally it is critical to study blood changes based on time intervals of measurements before, during, after the high-intensity training, and a period of recovery.