Bio-absorbable and biomimetic composites (HA-C) of hydroxyapatite (HAp) and collagen were designed utilizing salmon bone and skin at 298K and pH 7.5-7.9 by a dissolution-precipitation method. The HA-C powders were consistuted by Ca2+-deficient HAp containing small amounts of Na+ and Mg2+ ions and I type-collagen. Microstructure and surface characteristics of the HA-C powders gradually changed depending on the composition ratio of HAp to collagen (H/C). The HA-C powder of H/C=3.5 had frock like-agglomerated particles consisted of nano-crystals, micro-pore, and meso-pore so that it exhibited high specific surface area (75m2¥g-1) and large total pore volume (0.543 cm3¥g-1). From adsorption isotherms of water vapor at 298K for the HA-C powders, hysteresis - curves of the amounts of water vapor adsorbed were obtained in the adsorption-desorption processes. The amounts of water vapor adsorbed for the H/C=3.5 powder were the highest values under the relative partial pressures of 0.73-0.93. At 2 weeks after implantation of the HA-C powders into the subcutaneous tissue of the back region in rats, collagen was completely bio-absorbed and body fluid permeated into large agglomerated particles, although bio-absorption by multi-giant cell- infiltration was recognized around the surface layers of HAp particles.