miR-30a-5p inhibitors promoted expression of the osteogenesis factors Runx2, ALP, OC, COL1 and reduced expression of inflammation factors IL1R-1, IL1R-2, TNFR, accompany with miR-30a-5p mimics played reversed roles, which suggested miR-30a-5p played a regulatory role in the osteogenesis and inflammation of periodontitis. The gene discussed is IL1R2; the disease is periodontitis.