In the osteological field, the study of repairing and recovering processes for bone tissues has been one of the major clinical research subjects. To promote the bone healing, bioactive composite materials have been employed for the filling and supporting of defects, voids or diseased parts. In this study, a series of microsphere composites made from polylactide (PLA), a biodegradable polymer, and P-calcium phosphate (beta-TCP), an osteogenesis material, were prepared and estimated their potential applications in participation to the growth of new bone tissues on bone defects. By employing the water/oil/water (w/o/w) emulsion technique to fabricate a series of bioactive and biodegradable microspheres materials, we have found that one type of the microspheres: with diameter at 177 +/- 33 pm, and enclosure of beta-TCP at 18% (wt/wt), exhibiting smooth surface by the optical microscopy and scanning electron microscopy (SEM) observations, and showing slow yet steady calcium ion release and PLA degradation by in vitro test, showed excellent repairing and recovery of the chondrocyte and osteocyte tissues on drilled defects on the condyle of New Zealand rabbits within I month of application. (C) 2008 Wiley Periodicals, Inc.