The purpose of this study was to observe the histopathologic tissue reaction in vital bone in applying the various treated implants. For this purpose, twelve New Zealand Albino rats, weighing 3.3 to 4 kg were used as experimental animals. All the experimental groups divided into four groups; Machined surface as control, RBM(resorbable blast media), Hydroxyapatite-sand and Porous coating groups. All the experimental implants were examined under the scannning electron microscope. All the experimental rabbits were implanted in the tibial metaphyses of rabbits under the general anesthesia with Ketamine HCl(2.5ML /kg.body wt.) injections. For prevention of infection after implant, prophylactic erythromycine injections, 250mg/body wt.(Aldrich Co. USA) were performed on each. On the sixth week after implant, all the experimental rabbits were sacrificed with over dose of Sedaject(Samwoo Pharm .Co. Korea). All the tissues containing each experimental materials were fixed in ethyle alcohol, and embedded in spurr resin(Polytechnic Co. USA) as usual manner. sectioned in 12 um thickness, grinded , stained with the Vulenueva's osteochrome stain methed and examined histopatholgically. For measuring the distances between the implant and bone without any connective tissue interface, all the distances were calculated the length of the implant direct contact to bones. using the view analyzer program( Korea Optical Co.) and the statistical analysis were performed using the one-way ANOVA test. The statistical differences were considered significant below 5% level. Following results were obtained. On the scanning electron microscopic examination, dull cracked continuous linear indentations were revealed on the machined surface implant, irregular sharp indentation on the resorbabale blast, irregular thin exophytic or indentated leaflets on the hydroxyapatite-sand implant, and long ovoid globular particles were revealed on the porous coating implant surface respectively. On the histopathologic examination, complete osseointegation was noted between the implant and cortex bone on the collar and the apex lesion and in parts, small newley formed bone spicules attached to the screws in marrow tissues with compatibility in all experimental groups, but on the aspect of the tissue compatibility to the various implant materials, the superiority of the materials could not identified. The ratio of drect contact between the bone and implant, the HA sand gorup was the most superior among the gorups and followed by the machine surface, but on RBM and porous coating groups were inferior compared to that on the experimental groups. With these results, the superiority of tissue compatibility among the experimental implant group could not be identified