Objective To analyze the epidemic characteristics of a local infection outbreak caused by an imported dengue fever case in Zhangshu City,Jiangxi Province in August 2019,and to provide scientific basis for formulating dengue epidemic prevention and control strategies in the future. Methods Epidemiological investigation was carried out on dengue fever cases reported during the epidemic period.Mosquito vector density was monitored by double-layer overlapping method,mosquito trap egg method and bretu index method,and the data were collected and analyzed. Results A total of 743 cases of dengue fever were reported in this outbreak,the first case had a history of overseas travel.The cases were mainly distributed in the central urban area and four towns around the urban area.The age was mainly 28-69 years old(80.3%),and the gender ratio was 1∶1.12.The occupations were mainly commercial services (212 cases,accounting for 28.53%),housework and unemployment (200 cases,accounting for 26.92%) and farmers (199 cases,accounting for 26.78%).There were no severe cases and deaths.After the elimination of adult mosquitoes and breeding sources in the core area and the warning area,Monitoring sites with BI over 5 decreased from the highest 43.65% to 0,the mean biting index was controlled no higher than2 mosquitoes/person·hour in the core area. Conclusion Dengue outbreaks in Changshu City in 2019 were associated with out-of-country infections from travel to Thailand.