Objective To study the effect of peri-implantitis inflammatory microenvironment on the biological function of jaw bone osteoblasts.Methods Primary mandible osteoblasts from peri-implantitis and normal tissue were isolated and cultured. Third-generation purified osteoblasts were identified and detected. The proliferative activity of osteoblasts was evaluated through MTT assay. Osteocalcin (OCN), Runx2, and collagen?Ⅰ?(Col?Ⅰ) mRNA levels were examined by real-time quantitative poly-merase chain reaction. OCN protein levels were determined by Western blot.Results After 4 d of culture, the proliferative activity of osteoblasts from peri-implantitis became lower than that of normal tissue (PConclusion Peri-implantitis inflammatory microenvironment can decrease the proliferation and differentiation activity of mandible osteoblasts.