This studies examine release- of Ca and P from β-TCP, bovine bone and hydroxyapatite for malic acid and malonic acid which used dissolving chitosan. The other examine release from hardened specimen of bone filling materiales and analyzed X-ray diffraction pattern about residues. The main results obtained are as follows. 1. β-TCP was decomposed by malonic acid. 2. BB and HAP not decomposed by organic acid. 3. Mixture of β-TCP with malic acid showed the maximum amount of release for calcium and phosphate. 4. Mixture of BB with malic acid showed the minimum amount of release for calcium and phosphate. 5. Calcium and zinc appears to be selectively released from the hardened specimen. 6. Each apatite of bone filling materials were not decomposed.