Our results demonstrated that SeNPs reduced malondialdehyde (MDA), and advanced oxidation protein product (AOPP) levels, nitric oxide (NO) levels in stomach of ethanol-induced gastric ulcer, as well as the activities of Catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD); while glutathione (GSH) and non-protein thiols (NPSH) levels were restored reaching control values. Here, CAT is linked to gastric ulcer.