<；P>；PROBLEM TO BE SOLVED: To provide an osteogenesis promoting agent to promote osteogenesis, an osteoporosis preventing agent useful for the prevention of osteoporosis by promoting osteogenesis and a collagen synthesis promoting agent to promote the synthesis of collagen. <；P>；SOLUTION: The osteogenesis promoting agent, the osteoporosis preventing agent and the collagen synthesis promoting agent contain royal jelly or its extract as an active component. The osteoporosis preventing agent promotes osteogenesis and exhibits the action for the prevention or amelioration of especially senile osteoporosis. The osteoporosis preventing agent preferably further contains a bone resorption suppressing agent and/or a food material having calcium supplementing action. The collagen synthesis promoting agent increases the expression quantity of procollagen 1&alpha；1 gene by mixing with ordinary feed and orally administering to mouse (refer to the Example 1 shown in the Figure). The gene is known as a differentiation marker of osteoblast and plays an important role for improving osteogenesis function because the gene codes type-I procollagen which is a precursor of type I collagen constituting the main protein of bones. <；P>；COPYRIGHT: (C)2007,JPO&INPIT
