Abstract:  To further understand the epidemiological characteristics of human infection with avian influenza A （H7N9） virus in mainland China， a descriptive analysis was conducted according to the information on human H7N9 cases reported by national， provincial （municipal） department of health and China News via the Internet. Age， sex， occupation characteristics of human infections with influenza （H7N9） virus were analyzed. Meanwhile， comparative analyses were performed among the outbreak situations of different regione and time periods， and the migration time and routes of migratory birds. A total of 397 human H7N9 cases were reported from February 1， 2013 to May 12， 2014 by Chinese provincial （municipal） health service administrations websites. Among these cases， 261 were male patients， accounting for 671%， and 128 were women， accounting for 329%. The median age of infected people was 59 years old and they were mainly farmers and retirees. The middle aged and aged people were high risk groups for infection with H7N9 avian influenza. The eastern coast and southeastern coast areas in China were the key monitoring areas of avian influenza （H7N9）， where surveillance for migrant birds should be strengthened.

Key words: H7N9, avian influenza, epidemiology, bird migration