【Abstract】 Objective To grasp the population density and its seasonal fluctuation of primary vectors in Jinhua city，and to provide the scientific basis for the control of vector. Methods The light-trapping and cage-trapping were conducted to monitor the density of mosquitoes and flies respectively, as well as the night trapping and cockroach paste for rats and cockroaches. Results The average density of mosquitoes in Jinhua city was 12.47/(man·hour) from 2005 to 2007, of which, Culex pipiens pallens was the dominant specie, accounting for 94.46%, followed by Armigeres subalbatus (3.65%) and Anopheles sinensis (1.16%). Flies density index was 50.03/cage and Chrysomya megacephala and Lucilia sericata were the dominant species, which accounted for 36.05% and 24.56% respectively. The density of cockroaches was 126.74/100 nights·pages, and the dominant specie was Blattella germanica (97.95%). There were 135 rats caught and the rats density was 0.33%. Of which, the dominant specie was Rattus norvegicus (51.85%). Conclusion The main control targets  were Cx.pipiens pallens, Cx.megacephala, L.sericata, B.germanica as well as R.norvegicus in Jinhua city, so it should take the integrated measures to reduce the density of main vectors by firstly managing environment according to the characteristics of its breeding, habits and seasonal fluctuation.