Abstract: Abstract Objective: To understand the genetic characteristics of rubella viruses in Tianjin in 2009.Methods: Rubella viruses were isolated by Vero/SLAM cells and identified through RT-PCR.1170 nucleotides of E1 gene were amplified and sequenced.The phylogenetic tree of 10 rubella strains compared to the WHO reference strains for each genotype based on the 739 nucleotides of E1 gene was performed.Results: The 10 strains detected from Tianjin formed a distinct cluster in genotype 1E in the phylogenetic tree.The nucleotide sequence identities are 97.3%-100%. There was no change in the important antigenic epitope sites. Only one amino acide change（Trp234→Ser234）in Tianjing09-06 at the hemagglutination inhibition and neut ralization epitopes.Meanwhile the 10 strains isolated from Tianjin had the same amino acide change（Leu338→Phe338）in E1 protein.The result sustained other doctor’s research.The amino acide （Phe338）may only existed in Chinese 1E genotype rubella viruses.Conclusion: The rubella virus genotype circulated in Tianjin is 1E.The 10 specimens in this study clustered three close together in our phylogenetic analysis,suggesting that there may be multi-transmission routes in Tianjin.

Key words: Rubella viruses, 1E genetic type, sequence analysis