There are many important factors in periodontal inflammation. $IL-1{eta}$, $PGE_2$ and collagenase are predorminantly key factors. These inflammatory mediators induce gingival tissue and alveolar bone destruction. For the prevention and treatment of periodontal disease, it is necessary to inhibit $IL-1{eta}$, $PGE_2$ production and collagenase activity. Ursodeoxycholic acid(UDCA) has immunomodulatory properties, and there is evidence that some natural extracts show antiinflammatory activity to some degree. The purpose of this study was to assess the inhibitory effect of UDCA and its mixture with natural extracts on $IL-1{eta}$, $PGE_2$ production and collagenase activity. Accordingly we assessed the effect of UDCA and its mixture combined with some natural extracts on inhibition of $IL-1{eta}$, $PGE_2$ production and collagenase activity. For the $IL-l{eta}$ inhibition study, cultured cells were exposed to $25{mu}g/ml$ LPS. $IL-1{eta}$ activity was measured by $IL-1{eta}$ enzyme immunoassay system. Human gingival fibroblasts were prepared and cells (l05/well) were seeded into culture plates. $rhIL-1{eta}$ was added to induce $PGE_2$. The amount of $PGE_2$ in sample media was measured using enzyme immunoassay system. Crude collagenase was prepared from Porphyromonas gingivalis and collagenolytic activity was determined using a Collageno kit CLN-100. The test inhibitor was added to the assay mixture consisting of 0.1ml of 50mM Tris buffer(pH 7.5) and 0.2ml of substrate solution. UDCA and UDCA combined with natural extracts generally inhibited $IL-1{eta}$ production. groups above 0.01% UDCA strongly inhibited $IL-l{eta}$ synthesis. Both groups inhibited $IL-1{eta}-induced$ synthesis of $PGE_2$. In low concentration, the degree of inhibition was as same as prednisolone. In high concentration, each group was superior to prednisolone. UDCA group and UDCA mixture group exerted a moderate inhibition of collagenolytic enzyme. The present study suggested that UDCA and its mixture with natural extracts could be further investigated as antiinflammatory drug for periodontal disease.