[Background] Listeria monocytogenes is an important opportunistic pathogen. There are some differences in host range and virulence among different strains. Internalin gene inlA play an important role in host epithelial cells invasion. [Objective] Analyze the genomic characteristics of the Listeria monocytogenes STS477 isolate and investigate the genetic diversity of gene inlA. [Methods] Mutilocus sequence typing (MLST), single nucleotide polymorphism (SNP) and inlA genetic diversity were analyzed based on the sequencing data with software. [Results] MLST analysis showed that isolates from different countries have close relationship. Based on the SNP analysis, ST9 strains isolated from Canadian food owned the fewest mutation sites (91?93) by aligning six CC9 isolates against the chromosome of the ST477. The nucleotide homology of seven inlA gene sequences was 29.8%?100%. [Conclusion] We preliminarily analyzed the evolution of ST477 isolate and investigate the mutation type of inlA gene belonging to CC9. This study provides basic data for analysis of the evolution of ST477 strains and the virulence of L. monocytogenes.