Two sets of porous biphasic calcium phosphate ceramics (BCP) were prepared for dynamic SBF experiment: porous BCP with micropores on the walls of macropores( set A) and porous BCP with dense walls of macropores (set B). Apatite layer could only formed on the macropore walls with micropores. Four groups of specimens were prepared for animal experiments. Group A was porous BCP ceramics with micropores on the walls of macropores; group B was porous BCP with dense walls of macropores; group C was porous BCP ceramics with apatite layers formed by static SBFon their surfaces; group D was porous BCP ceramics with apatite layers formed by dynamic SBF on their walls of macropores. The result of dynamic SBF animal experiments showed that microstructure of BCP played an important role in the bone-like apatite formation and osteoinductiion in biomaterials. Apatite formation may be the prerequisite of osteoinductive formation of new bone.