Provided is an agent for preventing and/or treating osteogenesis imperfecta, osteoporosis and/or osteoarthritis, the agent comprising a peptide consisting of one of the following amino acid sequences: (a) Val-Asn-Pro-Glu-Ser-Glu-Glu-Glu (SEQ ID NO: 1) and (b) Val-Asn-Pro-Glu (SEQ ID NO: 2). The agent of the present invention can be orally ingested, has osteogenic function, and has a preventive and/or healing-promoting effect on bone fractures and is therefore very useful for prevention and/or treatment of osteogenesis imperfecta, osteoporosis and/or osteoarthritis.
