The present study has been performed to evaluate Porphyrornonas gingivalis (P.gingivalis) heat shock protein(HSP)bO as a candidate vaccine to inhibit multiple bacteria-induced alveolar bone loss. Rats were immunized with P.gingivalis HSP6O and experimental alveolar bone loss was induced by infection with multiple periodonto -pathogenic bacteria. Post-immune rat anti-P.gingivalis HSP IgG levels were significantly elevated and have demonstrated highly significant inverse relationship with the amount of alveolar bone loss induced by multiple bacteria. Results from PCR detection of subgingival bacterial plaque indicated that the vaccine successfully eradicated the multiple pathogenic species. We concluded that P.gingivalis HSP60 could potentially be developed as a vaccine to inhibit periodontal disease induced by multiple pathogenic bacteria.