Objective To explore the relation between the infection of Helicobacter pylori (H .pylori)and colorectal tumor.Methods From January 2012 to January 2013,the medical data of 152 patients with colorectal tumor were collected.According to the findings of colonoscopy examination, the patients were divided into the colorectal adenoma group (84 cases)and the colorectal carcinoma group (68 cases).A total of 88 healthy individuals were also enrolled as control.The differences of H .pylori infection were compared among the colorectal adenoma group,the colorectal carcinoma group and the healthy control group.The distribution of H .pylori infection in different age,gender and nation was analyzed in colorectal tumor group.According to the location,maximum diameter,number,type of pedicle and pathological type of adenoma,the colorectal adenoma group was divided into subgroups and the condition of H .pylori infection was compared among the subgroups.Chi-square test was used in the statistical analysis.Results The positive rates of H .pylori infection of colorectal adenoma group, colorectal carcinoma group and healthy control group were 70.2% (59/84),72.1 % (49/68)and 53.4%(47/88),respectively,where the former two groups were both higher than that of the healthy control group,and the differences were statistically significant (χ2 =5 .147 and 5 .637,both P 〈0.05).Regarding the H .pylori infection,there was no difference in age,gender and ethnicity among 152 patients with colorectal tumor (all P 〉 0.05 ).Among 84 patients with colorectal adenoma,there was no statistical difference in the positive rate of H .pylori infection in different location,maximum diameter,number, type of pedicle and pathological type of adenoma (all P 〉 0.05).Conclusion H .pylori may have promoting effects on the genesis and development of colorectal tumor. Key words: Helicobacter pylori ; Colorectal neoplasms; Colorectal adenoma