Abstract: Objective To observe the effects of clozapine on experimental gastric ulcer in mice. MethodsWater immersion restraint method: The mice were randomly divided into 5 groups (n=10): a normal saline (NSW) group, a model (W) group and 15 mg·kg-1, 30 mg·kg-1, 60 mg·kg-1 clozapine treatment (C15W, C30W, C60W) groups. Mice in the C15W, C30W and C60W groups were given the corresponding dose of clozapine 30 min before water immersion restraint, while those in the NSW and W groups were given normal saline alone. After eight hours, measurement was performed. Reserpine method: The mice were randomly divided into 5 groups (n=10): a saline (NSR) group, a model (R) group, and 15 mg·kg-1, 30 mg·kg-1, 60 mg·kg-1 clozapine treatment (C15R, C30R, C60R) groups. Mice in the C15R, C30R and C60R groups were given the corresponding dose of clozapine, while those in the NSR and R groups were given normal saline alone. After 30 min, the C15R, C30R and C60R groups were intragastrically administrated with 10 mg·kg-1 reserpine. After twelve hours, measurement was performed. ResultsWater immersion restraint method: Compared with the W group, the visceral pain index and gastric ulcer index were significantly decreased in the C15R, C30R and C60R groups (P<0.01). The ulcer inhibition rate: the C15W group < the C30W group < the C600W group. Reserpine methd: Compared with the R group, the visceral pain index and gastric ulcer index were significantly decreased in the C15R, C30R and C60R groups (P<0.01). The ulcer inhibition rate: the C15W group <the C30W group < the C60W group. ConclusionsClozapine has protective effects on experimental gastric ulcer in mice.