RESUMO
BK virus infection is one of the common complications after hematopoietic stem cell transplantation(HSCT), which is also one of the reasons of the hemorrhagic cystitis．In recent years, although there are more studies of the risk factors related with human BK virus infection after hematopoietic stem cell transplantation, the risk factors related with BKV-associated hemorrhagio cystitis(BKV-HC) remain to be elucidated. Diagnosis of BK virus infection is mainly based on quantitative PCR of blood or urine. An effective strategy for treatment of these patients is the adoptive transfer of T lymphocytes specific to virus-associated antigens. In this review, the progressis of diagnosis and treatment of BK virus infection after hematopoietic stem cell transplantation are briefly summarized.