Abstract: CHEN Jing-diao, Email: jingdiao_chen@sina.com Abstract:　Objective　The study was conducted to identify the phenotype and molecular biological characteristics of Brucella isolates in Guangdong from 2005 to 2006, and to determine their homology with previous isolates using pulsed-field gel electrophoresis(PFGE). Methods After conventional identification of the six strains of Brucella, species?鄄specific BCSP31 gene PCR and PFGE were conducted to determine their species and homology with other isolates. Results　Confirmed as Brucella melitensis biovar 3, all of the six strains presented positive specific BCSP31 genes, and the PFGE typing similarity between them ranged from 69.2% to 100%. Conclusion　Brucella melitensis biovar 3 as the only isolate identified in Guangdong for the last two years has demonstrated an alteration of species compared with the strains isolated in 1985. Furthermore, PFGE can be used to distinguish the three species of Brucella.