It is difficult to repair long defect of bone. Biological bone carrier (BBC) was one of the artifical bone substitutes. It was obtained from human or swine bone after a series of biochemical treatment. It had good histocompatibility. It had the same components and structure of bone, and its biological strength was samiliar to bone. In clinic, BBC was applied to repair of long defect of bone in two cases. The lengths of defect were 13 cm and 11 cm, respectively. After followed up for 2 to 3 years, it was found that the implanted BBC had been combined with the femur with new bone. It had the same metabolism and density as that of the normal bone.