Osteogenesis imperfecta, also known as brittle bone disease, is a congenital genetic disorder involving connective tissues of the skeleton, tendons, fascia, ligaments, dentin and sclera, and is characterized by increased bone fragility causing recurrent fractures and secondary bone deformities, dwarfism, and may be accompanied by blue sclera, triangular face, incomplete enamel production, joint and skin laxity or hearing abnormalities. The incidence is about 1/10,000 to 1/100,000. In 2004, Rauch et al. classified osteogenesis imperfecta into seven types, with the clinical severity of type II being the most severe, followed by type III, type IV and type VII being relatively mild, and type I being the least severe [2]. There is no radical cure for osteogenesis imperfecta, and clinical management mainly includes a combination of medications, orthopedic surgery and rehabilitation. In order to study the efficacy and safety of alendronate in the treatment of children with osteogenesis imperfecta, we gave alendronate orally to 11 children with osteogenesis imperfecta, and now 2. The dose was 5~10 mg/d, and physiological amount of calcium and vitamin D was supplemented.