The volatile chemical constituents of gamguk (Chrysanthemum indicum L.) produced in Korea, an aromatic medicinal herbaceous plant, were separated by the hydro distillation extraction method, and analyzed by gas chromatography-mass spectrometry. $alpha$-Pinene, 1,8-cineol, and chrysanthenone were the predominant aroma components. To investigate the bioactivity of the essential oil from gamguk, which at on bone metabolism, we studied the effects of it on the function of osteoblastic MC3T3-E1 cells were tested. It increased the collagen, alkaline phosphatase activity, and mineralization of osteoblasts significantly (p<0.05), indicating that gamguk may help prevent osteoporosis.