The subacute oral toxicity study of DWP-311 was carried out in Sprague-Dawley rats of both sexes. We daily examined clinical signs, body weights, hematological and biochemical parameters, and histopathological examinations for 30 days after administration of DWP-311 with different dose levels (0, 0.04, 0.2, and 1.0 g/kg). There were no clinical signs and pathological changes compared with control group except slight decreases in spontaneous motor activities and locomotions at high dose group of DWP-311. Body weights were not significantly changed in animals treated with DWP-311, In histopathological examinations, there were 2 cases of pneumonia in control group for one male and one female, but it was not directly related to DWP-311. These results indicate that subacute oral toxicities of DWP-311 were low and the no-observed a dverse effect level (NOAEL) was considered to be 1.0 g/kg in rats.