The effects of exercise training at the lactate threshold (LT) in fat oxidation in whole body were investigated. The 8 healthy men trained in cycle ergometer for 6-weeks (60min, 5times per week). They performed the fixed intensity exercise test at the workload of LT beforethe training (pre-LT), after the training (post0-LT) in each period, and at the workload of pre-LT (post abs-LT) again in the post-training period. The workload at LT before the training was 102+/-18watts, and increased to 131+/-21watts after training (p<.05). During the fixed intensity exercise test, the mean of oxygen uptake from 30' to 60' at pre-LT before training was 1583.2+/-203.5 ml/kg/min and 1541.97+/-230.1 at opst abs-LT and increased to 1893.1+/-343.4 at post LT (p<.05). The mean of RQ at pre-LT wad 0.90+/-0/03 and decreased to 0.84+/-0.03 at opst abs-LT (p<.05), and did not change at post LT. During the exercise at same workload, the 68% and the amount of FA oxidation to 60%. From these results, the advanced capacity of fat oxidation in skeletal muscle lead to inhibit glucose utilization.