Human avian-origin influenza A (H7N9)virus is a novel subtype of avian influenza A virus,which firstly emerged at the end of March 2013 in Shanghai and Anhui province.It rapidly spread in China within a short time,causing high morbidity and mortality,arousing fear and panic in public,and attracting extensive attention worldwide.The analysis of human H7N9 avian influenza virus gene shows a high affinity for α-2,6-linked sialic acid receptors expressed on human respiratory epithelial cells.At present,the sporadic cases of human H7N9 avian influenza virusare occasionally reported with an epidemic peaksat winter and spring.This article reviews clinical features,epidemiology and genetic characteristics of H7N9 avian influenza virus,proving scientific evidences foreffective prevention and control of H7N9 virus infection.