As the result of the study concerning "bone inducibility of chitosan", 1. "BMP-2"was observed mainly through the test when the "osteoblast"is exposed to the "chitosan". The expression of BMP-2 was 542.63 times compared to control after 2 hours exposure and it was maintained 16.60 times till 24 hours. 2. The expression of BMP-4 was decreased compared to control during exposure. 3. The expression of BMP-7 revealed two peaks during exposure. 4. The expression of osteocalcin was increased in early phase, and then decreased. Although it is not clear whether the "chitosan"is clinically effective material as a "bone induction material", we could say that it has a function for bone induction. Further detailed study will be required.