Objective To understand the epidemiological characteristics of the patients infected with avian influenza A(H7N9) virus,and explore possible sources of the virus. Methods 7 cases infected with avian influenza A(H7N9) virus and its related factors were investigated and analyzed from 2014 to 2017, according to investigation using questionnaire for the patients infected with avian influenza A (H7N9) virus of Anhui province (2017 edition). The relevant samples from the trading market of live poultry were collected to detect H7 nucleic acid. The clinical characteristics, risk factors and the impact of closing live poultry trading market on the epidemic were analyzed. Results 6 cases were male. The Median age of the 7 patients was 58 years old. Five cases were over 55 years old(71.43%). The cases were distributed in 7 different townships in 4 counties. They were mostly farmers (3/7).The onset time was concentrated in the winter and spring. The median of time interval between onset and treatment was 1 day (0~3 d).The median of the interval between the time of onset and taking the antiviral drugs was 4.5 days (3~6 d). All 7 patients had exposure to live poultry or live poultry market. After shutdown, the positive rate of H7N9 nucleic acid in the external environment of live poultry market decreased significantly(χ 2_{thend=11.92,P=0.001). Conclusion Live poultry exposure or exposure to live poultry market is a major risk factor for human infection with H7N9 avian influenza. Closing the live poultry market could help control the infection of H7N9 avian influenza.}