The metabolic way of calcium ions which was released due to in vivo degradation of porous β2TCP ceramics was studied by using the radioisotope 45Ca as tracer. The result shows that some of the calcium ions enter blood and take part in the circulation. These calcium ions distribute into organs and tissues (such as liver, kidney, brain, heart, lung, spleen and stomach) and participate in the metabolisms of body. There is neither the accumulation of calcium ions, nor the lesion or pathologic calcification of the organs and tissues. Some of the calcium ions that enter the near-end femur, ulna and skull are reused by bony tissue to take part in both local mineralization processes during bone healing, or are stored in calcium pool which can participate in the whole body circulating. In the cyclical process, other calcium ions are excreted with urine and feces through kidney and liver. It is indicated that the degradation products of β2TCP ceramics can take part in the physiological metabolic process of normal bone and tissue.