BACKGROUND Inflammation, ulcer and cancer are the popular diseases of stomach. The number of stomach cancer was placed on the second place after liver cancer and if reached a peak of 14,7% of all kind of cancer. Unfortunately, the number of these cases about stomach cancer took the second place, also the number of death caused by stomach cancer took the first place by it is happening. In Mongolia, because of stomach cancer around 500 people pass away. Helicobacter infection is considered as a main reason of stomach cancer and besides that, there are so many influencing factors such as smoking habits, nutrite, abuse of salt, genetic parameters. METHODS 537 patients have endoscopy done and 121 of them have analyze of helicobacter infection taken randomly in the 1st season of 2017 in gastroenterology department of Medipas hospital. The number of patients who have taken helicobacter analyze was computed by theorem of Japanese scientist Taro Yamane. Results of research was processed by spss-v.24. RESULTS 65 of patients, who were participated in this research were male and other 56 were female. Most of them were at the age between 40-50. 64% of them haven’t known about helicobacter and have never taken this analyze, 36% of them have taken analyze helicobacter in blood but they haven’t treated fully and haven’t known about infection of helicobacter by the way of transferring.