ABSTRACT
From April 2009 onward, a new strain of human H1N1 influenza virus has swept over the world. The genome of influenza virus consists of 8 segments, encoding 10 proteins, respectively. The reassortments among the 8 segments cause the variation of influenza virus. Therefore, phylogenetic analysis of the 8 genes is very important. In this paper, we choose neighboring word frequency as the genomic features, using VC++ programming to analyze evolution of the 8 segments of H1N1 virus. As a result, we found that PB2 genes and PA genes of these three isolated virus were originated from North American avian influenza virus, that PB1 genes were originated from the seasonal influenza virus of human, and that HA genes, NS genes and NP genes came from the North American classical swine influenza A virus. The NA segments and M segments were originated from the European swine influenza virus.