Abstract: Objective To get an insight into the distribution and seasonal fluctuations of the fly density and provide the basis for the control of flies and fly-borne diseases in Yangkang City. Methods Fly density monitoring was conducted from April to November once a month by cage traps. Each time, one monitoring spot was selected in farmers' market, two in restaurant-surrounding areas, one in city green belt and one in residential area, these were as the fixed monitoring points. Results A total of 681 flies were captured from 2009 to 2011 with an average fly density of 5.68/cage, of which the dominant species were Musca domesic, L. cuprina, M. sorbens. Their habitats listed in terms of the fly density in descending order of density were farmers' market, dining environment, residential community and green belt. The seasonal fluctuations of fly density followed a single-peaked curve, the high peak of which appeared in July and August. Conclusion There are several fly species in Yangkang City that can transmit disease, so it is important to strengthen the integrated monitoring to reduce the fly density for the control of fly-borne diseases.