A total of 499 stomachs consisted of 393 slaughter and 106 breeding pigs from industrial farm was examined for ulcerative lesions grossly and microscopically. The relationship between the ulcerative lesions and stomach contents was also examined. 1. The majority of stomachs has one or more lesions of ulcerative process, including parakeratosis(64.1%), erosions(10.2%), acute ulcers(2.8%), chronic ulcers(1.4%), and scars(0.8%). 2. The incidence and the degree of the esophagogastric lesions in the breeding pigs were similar to those of the slaughter pigs. But ulcerative lesions of the fundic lesions in the breeding pigs were found to be more remarkable than those of the slaughter pigs. 3. The stomach contents of the pigs having gastric ulcers were mostly fluid in nature, which were dry in the normal stomach. 4. Histologically, muscular hypertrophy, connective tissue hyperplasia and vascularity were shown in the ulcerative lesions of the esophagogastric portion. Thrombosis, necrosis and granulation tissue formation were found frequently.