Abstract: Objective To explore the relationship between different types of Helicobacter pylori(Hp)infection and attack risk of developing Henoch-Schonlein purpura(HSP)in children as well as clinical phenotype. Methods A total of 100 HSP children treated in Nantong City Second People's Hospital were selected as case group, and another 100 healthy children who underwent physical examination in our hospital during the same period were selected as control group. The change of Hp infection rates in the two groups was compared, and the clinical effects of different types on clinical phenotypes of HSP were observed. Results Hp positive rate was 35.00% in the case group,and 17.00% in the control group, and was higher in the case group than that of the control group(P<0.05); the levels of serum creatinine(Scr)and blood urea nitrogen(BUN)in Hp positive HSP children were significantly higher than those in the Hp negative patients(P<0.05). Meanwhile, the levels of serum cystatin C(CysC), tumor marker(TM), von willebrand factor(vWF), soluble vascular cell adhesion molecule-1(sVCAM-1), connective tissue growth factor(CTGF)and matrix metalloproteinase(MMP9)were also significantly higher than those in the Hp negative patients(P<0.05). In the case group, there were 35 Hp-positive patients, including17 with type Ⅰ, 6 with type Ⅱ and 12 with intermediate type. In the control group, there were 3 cases with type Ⅰ, 12 with type Ⅱ and 2 with intermediate type. The infection rate of type Ⅰ strain in the case group was significantly higher than that in the control group(P<0.05); the infection rate of type Ⅰ strain in children with digestive tract - symptoms or joint symptoms was significantly higher than that of the asymptomatic group(P<0.05). Conclusion The occurrence of HSP is closely related to Hp infection, and the pathogenic factors of Hp infection of different types are greatly differed. Type Ⅰ infection is associated with attack of HSP joint and injury of digestive tract as well as joint.