This study was performed to estimate the effect of plaque control on the progress of the repair pattern of the alveolar bone surface after bone surgery. In this experiment six mongrel dogs were used, four of them were as experimental group and others were as control. In the case of experimental group, dental floss ligature was tied over the neck of crown for permiting of plaque accumulation during one week before surgery and oral hygiene procedures were not performed. In control group, all the surgical intervention was done as same procedure with experimental except oral hygiene program. After surgery plaque was controlled during one week with using the chlorhexidine brushing. Animals were sacrificed at 1,2,4,6 weeks after osseous surgery. The results were as follows : 1. The alveolar bone defects were covered with regenerated epithelium at one week, matrix change of granulation tissue on subcutaneous area was observed, and new bone formation was initiated from the surface of the bone defects. 2. The connective tissue arrangement revealed more dense, new bone formation by osteoblasts was active at 2 weeks and proliferation of gingival epithelium and alveolar bone tissue were evident at 4 weeks, and almostly recovered to normal condition at 6 weeks. 3. In experimental group, inflammatory reaction was persistent in early stage and bone repair was delayed compared to control group. 4. In control group, matrix change of granulation tissue was initiated from one week, regeneration of gingival epithelium and maturation of subcutaneous conective tissue and new bone formation were evident at 2 weeks, so almost normal bone regeneration was observed at 4,6 weeks.