Objective To observe the effects of different pathological grades and renal impairment on circadian rhythm changes of blood pressure, especially nocturnal blood pressure in children with Henoch-Sch?nlein purpura nephritis (HSPN). Methods The clinical data of 121 children with HSPN diagnosed by renal biopsy were retrospectively analyzed, and the variation characteristics of 24 -hour ambulatory blood pressure were observed. According to the pathology classification of renal biopsy, the children were divided into gradeⅠ-Ⅱand grade Ⅲ-Ⅵ groups. According to the estimated glomerular filtration rate (eGFR), the children were divided into eGFR < 60 mL/(min· 1 . 73 m2 ) group and eGFR ≥60 mL/(min· 1 . 73 m2 ) group. The differences of ambulatory blood pressure levels and clinical indicators among different groups were compared. Results Among the 121 children with HSPN, there were 68 boys and 53 girls, with an average age of ( 8 . 8 ± 2 . 3 ) years. There were 105 cases ( 86 . 8 %) with abnormal blood pressure rhythms, and the incidence of hypertension was 31 . 4 %. The incidence of nocturnal hypertension was significantly higher than that of daytime hypertension (P<0.05). Compared with eGFR ≥60 mL/(min·1.73m2 ) group, 24 h mean systolic and diastolic blood pressure, daytime mean systolic and diastolic blood pressure, night mean systolic and diastolic blood pressure, 24 h urine protein quantity and blood creatinine were significantly increased, and gross hematuria duration was prolonged in eGFR<60 mL/(min·1.73m2) group, with statistical significance (P< 0 . 05 ). Conclusions The incidence of abnormal blood pressure of children with HSPN is high, and mainly characterized by the increased blood pressure at nighttime. The more severe the degree of renal damage in children with HSPN, the higher the nocturnal blood pressure, the more severe the proteinuria, and the longer the gross hematuria duration.