The active electrogastrogram (EGG) of 81 pilots under vestibular stimulus was recorded and analysed by the method of running spectrum analysis. The subjects were randomly divided into group A and B. The results showed: that changes in dominant frequency instability coefficient (DFIC), dominant power instability coefficient(DPIC), tachygastria, bradygastria and normal slow wave components (NSW) of EGG occured under vestibular stimulus. These parameters of EGG may be used as indices to reflect the function of autonomic nervous system under vestibular stimulus. No difference of those parameters had been found between group A and B during the period of per-rotating, and the period of rotation.