Objective To evaluate the effectiveness and feasibility of compound bone morphogenetic protein(BMP) with chitosan and cyanoacrylate on preventive absorption of rat’S alveolar ridge．Methods Fifry-four Wistar rats were divided randomly into three groups：Experimental group(compound BMP with chitosan and cyanoacrylate group)，control group(chitosan composite group)and blank group．After rat lower incisors were extracted，compound BMP with chitosan and cyanoacrylate were implanted into experimental group rat’S residual alveolar fossa，control group implanted with chitosan。blank group left empty．Animals were sacrificed after 3，6，9 weeks．X-ray examination，Image-Pro Plus analysis and pathologic observation were evaluated，Results The relative length Values of residual alveolar ridge and optical density test in experimental group were all greater than those of control group and blank group at 3，6，9 weeks after operation(P
