BACKGROUND: It has been reported that H.pylori causes changes in fundic leptin levels and plasma levels of ghrelin, and that eradication of H.pylori infection can increase appetite. There is also a report that showed changes of appetite between before and after eradication of H.pylori in peritoneal dialysis patients. Our study investigated the degree of appetite between H.pylori negative group and H.pylori positive group in adults. METHODS: The subjects included those without appetite- related diseases. We carried out gastroscopy and then performed CLO test in subjects who had no gastric lesions. We interviewed the study subjects about appetite related behavior (three items: desire to eat, hunger before meal, deliciousness) using visual analogue scale. We examined the appetite related behavior between CLO (??) group and CLO (+) group. RESULTS: The difference of age, sex, height, weight, body mass index, alcohol con sumption, blood pressure, hemoglobin, fasting blood sugar, AST, ALT, GGT between CLO (??) group and CLO (+) group were not statistically significant. The difference of appetite related behavior (three items) between CLO (??) group and CLO (+) group was not statistically significant. CONCLUSION: The degree of appetite between CLO (??) group and CLO (+) group was not different.