Objective To investigate Helicobacter pyloric (Hp) infection in children who underwent gastroscopy in Nanjing area.Methods From Jan.2001 to Dec.2010,2 990 pediatric patients with gastrointestinal symptoms who underwent endoscopy and Hp rapid urease test of gastric mucosa specimens.Results There were 2 990 patients who underwent gastroscopy during the 10 years including 1 718 cases of male and 1 272 cases of female.The rate of Hp infection was 53.8％ (924/1 718 cases) and 52.4％ (667/1 272 cases) in male and female,respectively.There was no significant difference (x2 ＝ 0.532,P ＞ 0.05).From Jan.2001 to Dec.2005,611 patients were tested and the rate of Hp infection was 66.9％ (409/611 cases).From Jan.2006 to Dec.2010,2 379 patients were tested and the rate of Hp infection was 49.7％.There was significant difference(x2 =58.13,P =0.01) between the 2 groups.The rate of Hp infection were 49.6％,48.1％,55.2％,60.0％ in 0-6 years group,＞6-9 years group,＞9-12 years group,and ＞ 12 years group,respectively.There was significant difference among the 4 different age groups (x2 =23.66,P ＜ 0.01).The rate of Hp infection in nodular gastritis(61.4％) was higher than that in chronic superficial gastritis (50.6％).There was significant difference between the 2 groups (x2 ＝ 7.42,P ＜ 0.01).The rate of Hp infection in allergic purpura (46.2％) was higher compared with the children with normal gastroscopy results (15.9％).There was significant difference between the 2 groups (x2 =10.19,P ＜ 0.01).Conclusions There is gradually downward trend by year in the rate of Hp infection of children who underwent gastroscopy in Nanjing area by year.The rate of Hp infection is increasing with the age after the age of 6 years.Hp infection may play a role in the nodular gastritis and allergic purpura.