Objective To analyze the related factors of helicobacter pylori(Hp) infections in children,and provide theory basis for prevention. Methods A total of 864 cases,aged 2 to 15 years old outpatient or hospitalized children with gastrointestinal symptoms in May 2007-May 2011,received the study of Hp infection assure R rapid serological screening positive for Hp stool antigen determination. Results Hp infection rate for children aged 2~15 in Lanzhou was 30.4%,the percentages of infection for male and female were 29.9% and 30.9%,respectively.There had an irregular increasing trend of Hp infection rate with the increasing of age,and the group aged 13~15 showed the highest infection rate.Hp infection rate of children whose parents had a history of gastroduodenal diseases was significantly higher than children whose parents without a history of gastroduodenal diseases.There had statistical differences.Hp infection in children in urban and rural had significant differences. Conclusions Hp infection rates for children aged 2~15 are at the higher level,and there are no difference between girls and boys.Hp infection was irregular increasing with the increasing of age.Family aggregation of Hp infection was shown in this study.