Objective To explore a new method for the therapy of avascular necrosis of the femoral head. Method The recombinant plasmid pCD-rbFGF was mixed with collagen and was implanted in the necrotic femoral head. Expression of basic fibroblast growth factor （bFGF） was examined by RT-PCR and immunohistochemical method. Re-pair of the femoral head was observed by histological and histomorphometric analysis. Result Expression of bFGF was detected in the femoral head transfected with bFGF gene

indicating significant increase of angiogenesis 2 weeks after gene transfection and increased new bone formation 8 weeks after gene transfection on histom-orphometric analysis （P< 0.01）. Conclusion Transfection of bFGF gene enhances bone tissue angiogenesis. Repair in osteonecrosis would be accelerated accordingly.