Objective To analyze the efficacy of kaolin intake amount as an index for motion sickness (MS)induced by different motion patterns stimulating the vestibular receptors of rats.Methods Rats were randomly divided into 5 groups.Three groups were subjected to one of the following stimulations,respectively-linear acceleration along either the interaural axis(IA)or body axis (AP),and double rotation(DR)stimulation.Other 2 groups were used as control.Kaolin intake was recorded for consecutive 6 d,3 d before and 3 d after stimulation,and the data were statistically analyzed.Results It was found that:1)following IA,AP and DR stimulations,25%,17% and 58% of the rats in each group increased mean kaolin intake by 1 g in the 3 d phase post-stimulation compared with that in the same duration of pre-stimulation,respectively;2)in contrast to some prewous reports,the present observation showed that high Ievel of kaolin intake post-stimulation may persist for more than one day.Conclusion All 3 tvpes of stimulation methods can serve as ways of specifically stimulating vestibular end-organs to induce kaolin intake increase,and double rotation iS the most effective.