OBJECTIVE: Hepatic veno-occlusive disease(HVOD) is one of the most serious complications after allogenic hematopoietic stem cell transplantation (allo-SCT). Endothelial injury, leading to deposition of coagulation factous in the terminal hepatic venules, is believed to the key event in the pathogenesis of HVOD. This study was designed to explore the efficacy of low-dose heparin and prostaglandin E1(PGE1) in the prevention of HVOD after allo-SCT in children with β-thalassemia major. METHODS: Forty-three children with β-thalassemia major received allo-SCT. For the prevention of HVOD, 23 of the 43 patients received low-dose heparin (100 IU/kg?d) and also received PGE1 (7.2 μg/kg?d) by continuous intravenous infusion (study group) from the beginning of conditioning treatment to the 30th day after allo-SCT. Patients who received continuous infusions of PGE1 (7.2 μg/kg?d) alone were used as the control group (n=20). RESULTS: HVOD occurred in 6 patients (26.1%) in the study group (3 mild, 3 moderate). Twelve patients in the control group had HVOD (60.0%) (3 mild, 3 moderate, 6 severe)(P<0.05). In the study group, 5 cases of HVOD were treated successfully and one died from other complications. Of the 12 cases of HVOD in the control group, 10 patients were treated successfully and two patients died from HVOD. There were no obvious drug adverse effects in the two groups. CONCLUSIONS: Low-dose heparin and PGE1 is more effective than PGE1 alone for the prevention of HVOD after allo-SCT.［Chin J Contemp Pediatr, 2007, 9 (4):343-346］