Abstract： Objective　To observe the changes of plasma renin and angiotensin levels and serum aldosterone level in rats with simulated motion sickness and after administration of compound ginger extract, in order to investigate the relations of hormonal endocrine with motion sickness and antimotion sickness function, so as to afford a new experimental basis for the prevention of motion sickness. Methods　Rats were stimulated with rotation to evoke motion sickness, and then plasma levels of renin and angiotensin and serum level of aldosterone were analyzed with radioimmunoassay. Meanwhile, the effects of compound ginger extract(containing crude drug 1 g/ml,p.o., 1.8 ml/200 g wt) on above humoral factors were observed. Results　The plasma renin and angiotensin levels and the serum aldosterone level were not elevated after rotatory stimulation. Compound ginger extract as anti-motion-sickness drug raised plasma angiotensin level and serum aldosterone level from(303.7±200.7)pg/ml to(607.2±196.1)pg/ml and from(664.2±248.6)pg/ml to(1081.5±256.7)pg/ml respectively. Conclusions　Combined with our previous reports and others, it is suggested that motion sickness is also a stress response; its development may relate to the state of low stress level of the susceptible subjects to abnormal motion stimulation, so that prevention of motion sickness may be attained by way of elevating stress level of the subjects susceptible to motion sickness.