Introduction: Humans sweat as a response to regulate body temperature, but only a few studies on the amount of both the variation in sweat rate and water consumption during badminton exercise have been conducted. Purpose: The purpose of this study was to survey changes in amount of water consumed, sweat rate and dehydration rate by handicapped badminton player during practice. Methods: The subjects were 24 competitive Asia-Olympic- or Japanese national level handicapped badminton player (18 males and 6 females) . Amount of water consumed, sweat rate, dehydration rate and WBGT were measured during exercise. Results: Mean amount of water consumed were 0.86 ± 0.21 kg, 1.13 ± 0.50 kg and 0.51 ± 0.19 kg (upper limb disorder class, lower limb disorder class and wheelchair class respectively) . Mean sweat rate were 7.30 ± 2.18 g/kg/hr, 8.57 ± 3.21 g/kg/hr and 5.99 ± 2.64 g/kg/hr (upper limb disorder class, lower limb disorder class and wheelchair class respectively) Discussion and conclusion: During summer, the athletes had nearly the same sweat rate during water exercise as land exercise, but consumed somewhat less water. The sweat rate was shown to be significantly higher in May than in August (P < 0.05), suggesting that the amount of sweat produced during water exercise is affected by the intensity of the regimen. It may be necessary to modify both the training environment and regimen and to encourage water consumptionduring aquatic exercise as actively as during land exercise.. Mean dehydration rate were 2.49 ± 0.67 %, 2.57 ± 0.96 % and 1.80 ± 0.79%.