PROBLEM TO BE SOLVED : To provide a food composition having excellent differentiation promotion effect to osteoblasts, further a differentiation promoter to osteoblasts, an osteogenesis accelerator and a pharmaceutical composition having therapeutic and/or preventive effect on bone weight reducing diseases.SOLUTION : There are provided a food composition containing royal jelly, glucosamine and chondroitin sulfate, a differentiation promoter to osteoblast, an osteogenesis accelerator and a pharmaceutical composition.