Recently, Platelet rich plasma(PRP) is commonly used because it is now well known that platelets have many functions beyond that of simple hemostasis in aspect of containing autogenous source of several growth factors. It could be responsible for increasing cell mitosis, increasing collagen production, recruiting other cells to the site of injury, initiating vascular ingrowth, and inducing cell differentiation, enhancing bone formation capacity and easily handling to clinician. However, in spite of these clinical advantages, still the theory behind the use of PRP is compelling. This study was to determine preparation techniques used to increase the concentration of platelets and growth factors are all crucial steps in early wound healing of bone graft which may lead to a more rapid and denser bone regenerate. 200 volunteers were sampled and PRP were prepared according to each evaluation item in this study. Higher concentration of platelets have been gained in double centrifugation. 2000 and 2500 rpm showed proper concentration of platelets at first centrifugation and 5000 rpm in second. Timing for 2 minutes was showed good concentration of platelets in high and low centrifugation speed. It was better concentration of platelets in 20 or 30 ml volume during centrifugation. In histomorphologic findings, degrnulated and high concentraion of platelets were found in low centrifugation speed.