Abstract： Objective To observe the toxic interaction of the 3 components (dextroamphetamine sulfate,dimenhydrimate and ginger extract) in the quick-acting anti-motion sickness capsule and evaluate safety of the drug. Methods LD50 of dextroamphetamine sulfate,dimenhydrimate,ginger extract and different combinations (i. e. dextroamphetamine sulfate-dimenhydrimate,dextroamphetamine sulfate-ginger extract,dimenhydrimate-ginger extract or dextroamphetamine sulfate-dimenhydrimate-ginger extract) were studied by using ICR mice. The interactive effects of the above combinations were determined with the Finney model.Results LD50 of dextroamphetamine sulfate,dimenhydrimate and ginger extract were 154.0 mg/kg,627.6 mg/kg and more than 24 g/kg. LD50 of dextroamphetamine sulfate-dimenhydrimate,dextroamphetamine sulfateginger extract,dimenhydrimate-ginger extract and dextroamphetamine sulfate-dimenhydrimate-ginger extract were evaluated to be 529.9 mg/kg,1834.0 mg/kg,1110.4 mg/kg and 1043.3 mg/kg respectively. Results showed that Q values of dextroamphetamine sulfate-dimenhydrimate,dextroamphetamine sulfate-ginger extract,dimenhydrimate-ginger extract and dextroamphetamine sulfate-dimenhydrimate-ginger extract were 0.93,0. 87,1.10 and 0. 88 respectively by using the Finney model. The interaction of the 4 combinations of the 3 components in the quick-acting anti-motion sickness capsule proved to be additive. Conclusions The toxic interaction of the 4 components ( dextroamphetamine sulfate,dimenhydrimate and ginger extract) in the quickacting anti-motion sickness capsule proved to be additive,rather than synergetic.