Objective To construct a new molecular biological method for the analysis of microbial species in lower respiratory tract infections based on 16S rRNA gene by denaturing high-performance liquid chromatograph(DHPLC).Methods The universal primer set was analyzed basing on the highly conserved regions of 16S rRNA gene.DNA amplicons of lower respiratory tract were analyzed by DHPLC to generate peak profiles respectively.The incorporation of 40-bpGC clamp into the amplification primet was essential to effectively discriminate genetic differences identification.Results The primers could only amplify bacterial 16S rRNA.Bacterial of amplicons which incorporation of a 40-bpGC clamp were effectively discriminated genetic differences in DHPLC.The results of clinical isolares identification showed 100%according with the traditional method.Conclusion DHPLC has not only high accuracy,but also is a convenient,rapid and high-through technique for the discrimination bacteria.It has potential value in the detection of lower respiratory pathogenic bacteria.