Abstract: OBJECTIVE To observe the effects of sodium p-hydroxybenzoate on the central nervous system and cardiovascular system of experimental animals. METHODS Kunming mice were given a single dose of sodium p-hydroxybenzoate of 20, 50 and 100 mg·kg^-1 by oral gavage, the effects of sodium p-hydroxybenzoate on the central nervous system were observed by mice tail-flick experiment, mice autonomic activity experiment, pole-climbing experiment, coordinating hypnosis test and Morris water maze experiment. SD rats were given a single dose of sodium p-hydroxybenzoate of 14, 35 and 70 mg·kg^-1 and Beagle dogs were given a single dose of sodium p-hydroxybenzoate of 4.2, 10.5 and 21 mg·kg^-1 by oral gavage, the effects of sodium p-hydroxybenzoate on cardiovascular system and body temperature were observed by measuring blood pressure and body temperature in Beagle dogs, and measuring electrocardiogram in SD rats. RESULTS There was no significant influence of sodium p-hydroxybenzoate on sensory-motor reflex, autonomic activity, coordinated movements, sleep rate of mice with the sub-threshold sleep dose of pentobarbital sodium and learning-memory ability. Similarly, there were no significant effects on electrocardiogram of SD rats and there were no significant effects on blood pressure and body temperature of Beagle dogs. CONCLUSION Single oral gavage of sodium p-hydroxybenzoate has no significant effects on the cardiovascular system and the central nervous system of experimental animal under the condition.