Abstract: OBJECTIVE To explore the relationship between genotypes of Helicobacter pylorii（Hp） infection and gastrointestinal diseases. METHODS A total of 258 patients with gastrointestinal diseases in Xinxiang Central Hospital between Jun 2017 and Jun 2020 were enrolled, including 112 cases with chronic gastritis（chronic gastritis group）, 98 cases with peptic ulcer（peptic ulcer group） and 48 cases with gastric cancer（gastric cancer group）. Hp genotypes were detected by polymerase chain reaction（PCR）, and their distribution in gastrointestinal diseases was detected. The relationship between genotypes of Hp infection and prognosis in patients with gastrointestinal diseases was analyzed. RESULTS The pepsinogen I（PG I）, pepsinogen II（PG II）, gastrin-17（G-17）, procalcitonin（PCT）, C-reactive protein（CRP）, percentages of neutrophils, lymphocytes and monocytes in the peptic ulcer group were significantly higher than those in the chronic gastritis group（P＜0.05）. PG I, PG II and percentage of neutrophils in the gastric cancer group were significantly lower than those in the chronic gastritis group（P＜0.05）, while G-17 level was significantly higher than that in the chronic gastritis group（P＜0.05）. The levels of PG I, PG II and CRP, and the percentages of neutrophils, lymphocytes and monocytes in the gastric cancer group were significantly lower than those in the peptic ulcer group（P＜0.05）, while G-17 level was significantly higher than that in the peptic ulcer group（P＜0.05）. The ratios of Hp infection genotypes（cagA, iceA, baba2） in the peptic ulcer group were significantly lower than those in the chronic gastritis group（P＜0.05）, while ratio of vacA genotype was significantly higher than that in the chronic gastritis group（P＜0.05）. The ratio of vacA in the gastric cancer group was significantly higher than that in the chronic gastritis group（P＜0.05）, while ratio of iceA was significantly lower than that in the chronic gastritis group and peptic ulcer group（P＜0.05）. The ratio of vacA subtype m2 in the gastric cancer patients with poor prognosis was significantly higher than that in the chronic gastritis group and peptic ulcer group（P＜0.05）. CONCLUSION Hp infection genotypes may be related to the severity of gastrointestinal diseases. The m2, which is the subtype of vacA genotype, may be related to poor prognosis of gastric cancer.