Objective To establish the spectra of metabolites that could be employed in identification of oral pathogenic bacteria, and try to find a convenient and rapid way to discriminate oral microorganism~ Methods Suspensions of Streptococcus muI,al~ ATCC 25175，Streptococcus sanguis ATCC 10556 and Lactobocillus ocidophilus ATCC 4356 witll same density were preparecd and cultured respectively at improved I liquid culture medium． The growth quantity were measured periodically by a turbidimeter．And the growth curves of the inoculated bacteria were completed．The culture solutions in stationary phase of the three bacteria were tested witll H-nuclear magnetic resonance (’H -NMR) spectroscopy respectively． The data of H —NMR spectroscopy results were analyzed by principal components analysis(PCA)．Results Th e PCA showed the obvious clustering phenomena and the points of three group diferentially centralized to three clusters．Therefore，the NMR—based metabonomi cs profiles could dis— criminate the three diferent kinds of bacteria+Conclusion Th e metabonomi cs is a promi sing new technology for developing to a rapid discrimi nation method of oral pathogenic bacteria．
