Objective:To study the effects of bacterial endotoxin with different concentrations on human gingival fibroblast (HGF) on titanium plate and its product osteoprotegerin(OPG), and to understand the healing function of endotoxin on soft tissue and bone tissue of dental implants. Methods:Tissue block culture method was applied to culture human gingiva and gingival fibroblasts were identified by immunofluorescence staining method. Endotoxin with different concentrations of 0,10 and 100 μg/ml were used to stimulate HGF on the titanium plate and HGF morphology was observed by scanning electron microscope(SEM). ELISA was applied to detect the OPG level. Results:Compare with the normal group,the HGF stimulated by endotoxin of 10 μg/ml had more cellular pseudopods and cellular matrix secretion was increased. However, in the 100 μg/ml endotoxin stimulated group,number of cells and cellular matrix secretion were decreased significantly. ELISA method demonstrated that under the condition of low concentration, OPG increased with the increase of endotoxin concentration. But the OPG level of 100 μg/ml group decreased significantly. Conclusion:Low concentration of bacterial endotoxin can promote growth of HGF and secretion of cellular matrix OPG;whereas high concentration of bacterial endotoxin can inhibit growth of gingival fibroblasts and decrease OPG level.