Naturally ventilated sports buildings in Guangzhou were taken as studied object in this study, and the parameters of indoor thermal environment and the thermal sensation votes of exercising people and spectators were collected by field measurement and questionnaires respectively. The adaptive thermal comfort models and comfort ranges of these two groups of people were initially established and then compared. The results showed that the thermal sensitivity of exercising people in the natural ventilation sports building is 0.326 6, which is lower than that of spectators (0.379 9). The neutral temperature of exercising people and spectators increases with the increasing of outdoor air temperature, which of the former is 0.80℃ to 1.48℃higher than that of the latter. And the upper and lower limits of thermal comfort range of exercising people and spectators increase with the increasing of outdoor air temperature, and the lower limits of thermal comfort range of the former is similar as that of the latter, while the upper limits of thermal comfort range of the former is 1.86℃ to 2.48℃ higher than that of the latter.