One of functions of Galla Rhois (GR) is reportedly an anti-inflammatory effect on the several inflammatory diseases. However, an effect of GR related to periodontitis has not been investigated. In the present study, we examined the effect of the hexane extract of Galla Rhois (GR-H) on periodontitis. Cytotoxicity was assessed by MTS analysis using human gingival fibroblast (hGF) cells. Experimental periodontitis was induced by injecting E.coli LPS into the palatal gingiva maxillary molar thrice weekly for 3 weeks (LPS group). GR-H diluted in 1xPBS was orally administrated using a syringe at 30 mg/kg body weight and 100 mg/kg body weight once a day (GR-H group). GR-H effect on the alveolar bone loss (ABL) was digitized with a micro-CT. GR-H treatment at concentrations exceeding 0.5 mg/ml showed cytotoxic effect in hGF cells. The micro-CT among groups were presented for the different distances from cemento-enamel junction (CEJ) to alveolar bone crest (ABC). The results indicated an inhibitory effect on alveolar bone loss for orally administered GR-H in a model of LPS-induced periodontitis.