Several growth factors and polypeptides were studied for the regeneration of periodontal supporting tissues which had been lost due to periodontal disease. But these are not commonly used for regenerators of bone tissue or alveolar bone, because of the insufficiency of studies on their side effects, genetic engineering for mass production and stability for clinical application. Recently, many natural products, which have advantage of less side effects and possibility of long-term use, have been studied for their capacity and effects of anti-bacterial, anti-inflammatory and regenerative potential of periodontal tissues. Cnidii Rhizoma , Rhinocerotis Cornu and Drynariae Rhizoma have been traditionally used as a drug for treatment of bone disease in oriental medicine. The purpose of this study was to examine the ability of alkaline phosphatase synthesis of MC3T3-E1 cells when above medicines were supplimented. MC3T3-E1 cells were cultured with α-MEM(negative control), dexamethasone(positive control), and each natural products for 3 and 5 days. And then ALP synthesis was measured by spectrophotometer for enzyme activity and by naphthol AS-BI staining for morphometry. Except Cnidii Rhizoma , all of the natural products of this study induced higher activity of ALP synthesis than controls. Among them Drynariae Rhizoma induced the highest activity. In the aspects of culturing time, all medicines did not showed the difference between 3 and 5 days, but 10^-7g/ml group of Rhinocerotis Cornu showed significant increase at 3 days than at 5 days. These results indicate that several natural products have a inducing ability of ALP synthesis on osteoblasts.