Objective To investigate epidemiological characteristics of imported dengue fever in Daozhen county, the species and density of local Aedes mosquitoes, and provide basis for prevention and control. Methods Epidemiological investigation was carried out on dengue fever cases and other returnees in July 2016. The dengue IgM antibody of the serum returnees were detected by ELISA, and investigating the Aedes mosquitoes in the town where the cases reside was carried out by human baiting and Breteau index(BI). Results There were 5 clinical cases, 2 suspected cases, 1 asymptomatic infection among all 26 returnees from Maldives, with morbidity rate 30.77%. Six sera were positive for dengue IgM antibody, 7 cases were treated and recovered. Other 19 asymptomatic individuals were quarantined for 14 d, and no new clinical cases emerged. Investigating the Aedes mosquitoes in towns of Yuxi, Hekou, and Zongping revealed that landing rate on human was 2.4, the mosquito density was more than C level (human landing rate less than 1.5). BI was 7.0, slightly higher than the threshold for the spread of dengue fever (BI ≤ 5). Conclusion An imported dengue fever outbreak from Maldives occurred in Daozhen county in 2016. There was no secondary dengue transmission locally, because of the effective preventive measures.