Abstract: Objective　To explore the treatment and mechanism of platelet transfusion refractoriness in pediatric hematological disorders. Methods　Retrospective analyses were performed from 4 children diagnosed with platelet transfusion refractoriness between 2013 and 2014 in Children’s Hospital of Soochow University. Clinical manifestation, laboratory tests, and the effect of plasma exchange were evaluated on pediatric platelet refractoriness. Results　Two males and two females with age ranged from 2 years to 11 years and 9 months met the criteria of platelet refractoriness. Three cases were diagnosed as AML-M5 (M5), and one case was diagnosed as severe aplastic anemia (SAA). Platelet refractoriness occurred in one case of M5 after induction chemotherapy, and two cases in the stage of hematopoietic stem cell transplantation (HSCT). The SAA patient showed platelet refractoriness on her admission. The screening for HLA antibodies with the method of Immune Luminex beads streaming technology (Luminex) revealed that HLA-I antibody reaction were positive in three patients. All four patients showed a good response to the treatment of plasma exchange. Conclusions　HLA-I class antibodies are closely associated with platelet refractoriness, the plasma exchange treatment is effective and safe for platelet refractoriness in children.