H7N9 virus is a novel avian-origin virus. The hemagglutinin (HA) and neuraminidase (NA) of the virus play key roles in the interspecies transmission, viral replication and pathogenicity. One of significant characters of H7N9 is that it has no noticeable pathogenicity among poultry, but is highly pathogenic for human being and is associated with high mortality. H7 subtype avian virus can be compatible with different NA subtypes, and has caused many infection events in human being. It can be predicted that the influence of H7 subtype avian influenza A virus will persist and lead to serious public health problem, and therefore deserves more attention. Establishment of prevetion and control network can help to reduce the threat of H7N9 virus to human health.