Abstract: OBJECTIVE To observe the effects of Sonchus oleraceus powder suspension on the central nervous system and cardiovascular system of experimental animals so as to provide evidence for further clinical study and safty medication. METHODS ICR mice were given a single dose of Sonchus oleraceus powder suspension of 0.13, 0.39 and 1.17 g·kg^-1 and SD rats were given a single dose of Sonchus oleraceus powder suspension of 0.09, 0.27 and 0.81 g·kg^-1 by oral administration, the effects of Sonchus oleraceus powder suspension on the central nervous system were observed by mice autonomic activity experiment, coordinating hypnosis test and rat rotating rod experiment. Beagle dogs were given a single dose of Sonchus oleraceus powder suspension of 0.03, 0.09 and 0.27 g·kg^-1 by oral administration, the effects of Sonchus oleraceus powder suspension on cardiovascular system and body temperature were observed by measuring electrocardiogram, blood pressure and body temperature in sober Beagle dogs. RESULTS There were no significant in fluence of Sonchus oleraceus powder suspension on autonomic activity, coordinated movements and sleep rate of mice with the sub-threshold sleep dose of pentobarbital sodium. Similarly, there were no significant effects on electrocardiogram, blood pressure and body temperature of Beagle dogs. CONCLUSION Single intragastric administration of Sonchus oleraceus powder suspension has no significant effects on the cardiovascular system of Beagle dogs and the central nervous system of ICR mice and SD rats under the condition.