〔Abstract〕 Objective To investigate the relationship between red blood cell distribution width (RDW) and Henoch-Schonlein purpura nephritis (HSPN) in children. Methods A total of 50 children with HSPN admitted to Children's Hospital Affiliated to Zhengzhou University from April 2018 to April 2021 were selected as the HSPN group, and 50 children with Henoch-Schonlein purpura (HSP) and 50 healthy children who underwent physical examination during the same period were selected as HSP group and healthy group respectively. The three groups were compared in terms of blood routine indexes and RDW levels in children with different pathological grades of HSPN, and the correlation between RDW and HSPN were analyzed.Results The white blood cell and neutrophil counts in the HSP group and HSPN group were higher than those in the healthy group, and the hemoglobin and RDW in the HSPN group were higher than those in the HSP group, and the differences were statistically significant (P < 0.05). The RDW level of children with grade HSPN Ⅱ, Ⅲ were higher than those of the grade Ⅰ, and the RDW level of children with grade HSPN Ⅲ was higher than that of the grade Ⅱ, and the differences were statistically significant (P < 0.05). Spearman correlation analysis showed that the condition severity of HSPN was positively correlated with RDW (r = 0.794, P < 0.001). The results of receiver operating characteristic (ROC) curve showed that when the cut-off value of RDW was 13.5 %, the area under the curve was 0.964, 95 % CI (0.932, 0.996), P < 0.001, the sensitivity was 98.00 %, and the specificity was 88.00 % for the diagnosis of HSPN. Conclusion The RDW is positively correlated with the severity of HSPN in children, which has a certain value in the diagnosis of HSPN in children and can provide reference for clinical treatment.