Objective: To compare the outcomes of guide bone regeneration calcined bovine bone and Bio-Oss graft material in alveolar ridge preservation after tooth extraction.Methods: 280 patients were divided into two groups randomly.Each patients single-tooth was extracted.The sockets were filled with guide bone regeneration calcined bovine bone and Bio-Oss graft material respectively.After shaped, all the sockets were covered with Bio-Gide membrane.Buccal mucoperiosteal flap was released and sutured to close the alveolar sockets.The patients were regularly examined at the 1 st, 12th and 24th week.Physical examination and X-Ray evaluation were applied to compare the outcomes of the two materials in alveolar ridge preservation.