The purpose of this study was to investigate the effects of thermoplastic insole on physiological responses in endurance running. Subjects were 7 male university runners age 20.9±1.2 years height 1.71±0.07m weight 61.7±4.7kg, VO2 65.0±6.2ml/min/kg. The subjects performed thirty minutes running in 70%VO2max running speed with two different conditions (shoes with insole and shoes without insole). VO2, the concentration of blood lactate acid, heart rate, RPE were measured during thirty minutes endurance running. The trials were divided into three 10 minutes phases. The analysis values were averaged for each phase and compared between the phases and between conditions. RPE was significantly lower in insole condition than in no condition, and increased significantly between each phase. However, there were no significant differences in VO2, the concentration of blood lactate acid and heart rate between phases and insole condition. These results suggested that thermoplastic insole does not limit performance in endurance running, and reduces runner's subjective fatigue.