Abstract: Objective To construct vectors expressing siRNA against tumor necrosis factor receptor associated factor 6 (TRAF6) gene and to examine its interference effect on murine odontoblast-like cell line(MDPC-23).Methods Two target gene segments were synthesized and cloned into pSUPER vector,respectively,to construct two recombinant eukaryotic expression vectors(pSUPER-T and pSUPER-2T).The two recombinant vectors were identified by enzyme digestion analysis and DNA sequencing.Then MDPC-23 cells were transfected with pSUPER-T or pSUPER-2T and the interference effect was detected by reverse transcription(RT)-PCR and western blot.Results The results of RT-PCR and western blot indicated that both vectors could effectively down-regulate the transcription and expression of TRAF6 gene,and that pSUPER-2T had better interference effect than pSUPER-T.Conclusion The transcription and expression of TRAF6 gene in MDPC-23 cells were inhibited effectively by the constructed RNAi eukaryotic expression vectors,which will facilitate further studies of TRAF6 function and its application in the treatment of disease.