Objective: In this study, the effects of baicalin -a flavonoid purified from Scutellaria baicalensis. Georgi, Scutellaria L. -on alveolar bone resorption in rat experimental periodontitis were examined. Method: 12 Sprague-Dawley rats (SD rats) were randomly divided into four groups: Group A1, A2, B and C. Except for Group C -the control group-, Group A1, A2 and B were used to establish the rat periodontitis model by repeat injection of Lipopolysaccharide (LPS). At the same time, Group A1 and A2 were injected with baicalin of different concentration. 9 days later, the maxillae were extracted and analyzed using micro computerized tomography (micro-CT), followed by histological analysis. Result: Micro-CT images showed that alveolar bone resorption was severely induced around the molar by repeat injection of LPS. Treatment with high-dose baicalin (1.0 μg / ml) clearly recovered alveolar bone resorption, meanwhile, low-dose baicalin(0.1 μg / ml) showed a similar but weaker effect. Histological examination clarified that the number of osteoclast was dose dependently decreased by baicalin treatment. Conclusion: These findings suggest that baicalin may inhibit the alveolar bone loss in periodontitis effectively. Keywords