The chromatograms of pyrolysis gas chromatography (PGC) of fifteen strains of Salmonella typhi were reported to see if there is any possible relation of the graphs to serological typing and drug-resistance spectra of the bact. In the fifteen strains there were fourteen clinical strains and one reference strain (Hg01). The results indicated that the clinical strains might be divided into group A and B (7 strains each) by PGC. The graphs drawn from group A organisms were entirely the same in shape while those of group B showed only basic similarity. According to the diversity of graphs of group B organisms, the group B organisms, may be subdivided into group B1 (4 strains), B2 (2 strains) and B3 (1 strain). The graphs within each subgroup were completely the same and those of subgroup B1 exhibited close similarity to that of the reference strain. Albeit no regular connection of chromatograms with serological types and drug-resistance could be seen, the graphs yet provided useful reference for founding a bank of chromatograms, compaed with which salmonella typhi graph could then be identified.