Abstract: Objective: The main reason for restoration failure is secondary caries at the tooth-restoration margins, caused by acid production by biofilms. The objectives of this study were to incorporate quaternary ammonium dimethylaminododecyl methacrylate (DMAHDM) into dental adhesive resin and to investigate their effects on antibacterial and dentin bonding properties. Methods: DMADDM was synthesized and incorporated into a commercial dentin bonding agent at mass fraction of 10%. The dental plaque microcosm biofilm model was used to evaluate biofilm viability. The dentin bond strength was measured in 4-point flexure test before and after water-aging or biofilm incubation for 14 days. Results: Incorporating DMADDM significantly reduced the biofilm viability. 14-day biofilm degradation had much less influence on the bond strength of dental adhesive resin containing DMADDM. Conclusions: Bonding agent containing DMADDM had strong antibacterial potency and could resist the oral environment degradation. The novel dentin bonding agent may have wide applicability in clinic.