Abstract: Objective　To observe the percentage of Th17 cells in peripheral blood mononuclear cells (PBMCs) and the serum level of interleukin-17 (IL-17) in children with Henoch-Schönlein purpura (HSP). Methods A total of 30 HSP children and 20 healthy children were selected. The percentage of Th17 cells in PBMCs was measured by flow cytometry analysis and the serum level of IL-17 was measured by ELISA method. The results were compared between HSP children and healthy children. Results The percentage of Th17 cells in PBMCs in HSP and healthy children was (2.14 ± 0.90)% and (0.84 ± 0.41)%, respectively, and the difference was significant between two groups (P<0.05). The serum levels of IL-17 in HSP and healthy children were (38.36 ± 13.44) pg/ml and (10.59 ± 4.17) pg/ml, respectively, and the difference was also significant (P<0.05). Conclusions The percentage of Th17 cells in PBMCs was obviously increased in HSP children. It is suggested that Th17 cells may play a role in the pathology of HSP.