To establish polymerase chain reaction (PCR) technique for the detection of specific genes related to species of genus Bartonella, and for diagnosing clinically suspected cat-scratch disease (CSD) case complicated with pneumonia on both lungs. The appearance of Bartonella infectious diseases calls for genus and species detection and tools for identification in order to make clinical diagnosis and carry on epidemiological studies.One pair of primer TIle.455p-TAla.885n was designed based on the fact that tRNA(Ile)-tRNA(Ala) intergenic spacer region in 16S-23S rRNA intergenic spacer (ITS) of genus Bartonella were high variable sequences flanked by completely conserved tRNA-encoding genes. 16S-23S rRNA was longer than that which had been described in other bacteria. Two published pairs of primers were used to directly detect the specific gene fragments of Bartonella species DNA extracts from human blood, followed by PCR product Sequencing and nucleotide base sequence analysis.Amplification products of the three pairs of primers had the same predicted size of those in Bartonella spp. According to the different length of electrophoresis bank, the sample was identified as a species of genus Bartonella other than the positive control. Sequence analysis showed that the nuleotide sequence from the PCR product of primer TIle.455p-TAla.885n was identical to the Bartonella isolated from Yunnan in China.PCR-based assay provided a simple and rapid means to detect pathogenic Bartonella species in humans and mammalian hosts as well as in arthropod vecters. This study suggested that this pathogenic Bartonella species existed in patients in northern and southern parts of China.