Abstract: Objectives　To investigate the etiology, renal pathology, treatment, and prognosis of children’s urinary system injury after hematopoietic stem cell transplantation (HSCT). Methods　Clinical data of 81 children with urinary dysfunction after HSCT admitted to the Hematology Department in Children’s Hospital of Soochow University were analyzed, and relevant literatures were reviewed. Results　In 81 cases (50 males and 31 females), the age ranges from 8 months to 17 years old. Thirty cases (37%) with prerenal injury were recovered after active rehydration and other symptom specific treatment. There were 9 (11.1%) children with renal injury, four cases were given up therapy or transferred to other hospitals, thus lead to an unknown prognosis. Kidney biopsy was performed in the remaining five cases for pathological investigation. After active symptom-speific and etiology-based treatment,  serum creatinine and glomerular filtration rate of four cases return to normal. But in the long-term follow-up，one case died of recurrence of primary disease, reinfusion of hematopoietic stem cell combined with renal failure. The remaining 3 patients were with chronic kidney disease (CKD). One case with renal thrombotic microangiopathy was in the chronic dialysis. Postrenal renal injuries were mainly hemorrhagic cystitis (28.4%) and urinary tract infection (16%). After a large dose of rehydration, urine alkalization and anti-infection therapy, they were recovered in the short term with a good prognosis. Conclusions　Urinary injury after HSCT is mainly divided into three categories: prerenal, renal and postrenal, in which renal injury is prone to frequent recurrence.