中文摘要：

H9N2亚型流感病毒是低致病性流感病毒，严重影响养殖业的发展，并且具有感染哺乳动物的能力，威胁人类健康；能够与其他流感病毒重组，产生新型流感病毒，有造成流感大暴发的潜在风险。本文列举了H9N2亚型流感病毒的生物学特性，总结近年来H9N2的流行情况，致病性改变和其作为新型流感病毒的基因供体等几个方面的研究，阐述H9N2亚型流感病毒的潜在危险性。

英文摘要：

The low pathogenic avian influenza H9N2 virus is able to infect mammal, seriously affecting the development of aquaculture and threatening the health of human. It can be recombined with other influenza virus and produce new virus types, which have the potential risk of causing flu epidemic. This article lists the biological characteristics of influenza H9N2 virus, and elaborates the potential risk of influenza H9N2 virus by summarizing the prevalence of H9N2, its pathogenic changes and acting as the gene donor for new influenza viruses in recent years.