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.