Abstract: ［Abstract］Objective　To study the regularity of incidence，prophylactic training and readaption of motion sickness in hot-humid environment by 3 experiments．Method（1）We tested the incidence of motion sickness and the grading of severity of all the subjects in room temperature，hot and hot-humid environment．（2）We evaluated the training effect of two-stage training for motion sickness. （3）We did the adaption research on those subjects who had already adapted．Results　（1）Incidence and grading of severity of motion sickness between room temperature and hot environment were different（P＜0.05）；Incidence and grading of severity among 3 environment were different（P＜0.01）. （2）Incidence and grading did not change through environment adapted training（P＞0.05），while they changed through anti-dizzy training（P＜0.05）. （3）Readaption effect was not different for those subjects who had been adapted after 3 months（P＞0.05）．Conclusions（1）Incidence and grading of severity for motion sickness are greater in extreme environment. （2）Environment adapted training is useless， while anti-dizzy training is useful. （3）Plastochrone for adapted training should be within 3 months.