Fabrication, in vitro degradation and cytotoxic assay of different crystalline phases calcium polyphosphate (CPP) were reported. The CPP ceramics were fabricated by crystallizing the amorphous frits , and sintered at 550 ℃ ,875 ℃ ,1000 ℃ for 1 h to obtain the γ-CPP, β-CPP anda-CPP respectively. The effects of the different crystalline phases on their weight loss and released PO4 3- were investigated during the degradation.And the surface change was observed by the SEM. The osteoblastic ROS17/2.8 cell line was used to estimate the cytotoxicity of CPP. The effects of CPP on cells' proliferation were evaluated by using MTT assay. The experimental results showed that γ-CPP, β- CPP and α-CPP did not exert cytotoxic effect on the cells. In addition, the proliferation of the growth of ROS17/2.8 cells on β-CPP was optimal.