Recently, many natural medicines, 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 for periodontal tissues. Cortex Eucommiae, Eupoly phaga, Semen Cuscutae, Halloysitum Rubrum have been traditionally used as medicines for treatment of bone disease in Korea. The objective of the present study is to examine the ability of alkaline phosphatase (ALP) activity in human fetal osteoblast cell line (hFOB1) with several natural medicines. hFOB1 added DMEM/F-12 were cultured with dexamethasone as a positive control, and with each natural medicine. ALP activity was measured by spectrophotometer for enzyme activity and naphthol AS-Bl staining was performed for morphometry. All of the natural medicines induced a higher ALP activity compared to negative control, especially, Cortex Eucommiae increased an ALP activity in all experimental groups (p<0.05). In naphthol AS-Bl staining, all of the natural medicines of this study increased the stained area compared to negative control. Especially, Cortex Eucommiae and Eupoly phaga showed statistical significance compared to negative control (p<0.05). These results indicate that Cortex Eucommiae, Eupoly phaga, Semen Cuscutae, Halloysitum Rubrum have an inducing ability of ALP synthesis on osteoblasts.