The ultimate goal of periodontal disease therapy is to promote the regeneration of lost periodontal tissue, there has been many attempts to develop a method to achieve this goal, but none of them was completely successful. This study was designed to compare the effects of treatment using resorbable barrier membrane($Biomesh^{?}$) in combination with autogenous bone graft material with control treated by only modified Widman flap. 22 infrabony defecs from 10 patients with chronic periodontitis were used for this study, 10 sites of them were treated with resorbable barrier membrane and autogenous bone graft material as experimental group and 12 site were treated by only modified Widman flap as control group. Clinical parameters including probing depth, gingival recession, bone probing depth and loss of attachment were recorded at 6-8 months later, and the significance of the changes was statistically analyzed. The results are as follows : 1. Probing depth of the two group was reduced with statistically significance(P<0.05), but this changes were not different between the two experiment, control group with statistically significance. 2. Gingival recession showed statistically significant increase in control group(P<0.05), but not in experimental group, and initial values of the two group were in statistically significant difference(P<0.05). 3. Bone probing depth showed statistically significant decrease in experimental group(P<0.05), but not in control group, and this changes were different between the two experiment, control group with statistically significance(P<0.05). 4. Loss of attachment showed statistically significant decrease in experimental group(P<0.05), but not in control group, and this changes were different between the two experiment, control group with statistically significance(P<0.05) On the basis of these results, treatment using resorbable barrier membrane in combination with autogenous bone graft material improve the probing depth, bone probing depth and loss of attachment in infrabony defects.