As of August 2017, China had encountered five seasonal epidemics of H7N9 avian influenza. To prevent people from contracting H7N9 avian influenza, most cities closed live poultry markets (LPMs) to cut off the source of H7N9 virus. The objective of this study is to assess the impact of LPMs closure on reducing zoonotic transmission of avian influenza A (H7N9) virus and to make specific recommendations on the duration of closing the LPMs. Results show that the closure of LPMs can effectively control the spread of H7N9 avian influenza and reduce the incidence of human infection with H7N9. If cases of H7N9 avian influenza continue to occur, LPMs should close for at least 3-4 weeks in susceptible areas to control the spread of infection.