Objective To identify the species compositions and densities of vectors in Shenyang, China during 2008-2010 and to provide technical support for the prevention and control of vector-borne diseases. Methods Rodents, mosquitoes, flies, and cockroaches were monitored using traps set at night, mosquito lamps, cage traps, and glue traps, respectively, to determine their species and densities. Results From 2008 to 2010, the rodent densities were 0.31%, 0.18% and 0.16%, respectively, with the highest density found in rural areas, and the dominant species was Rattus norvegicus. The adult mosquito densities were 8.56, 10.52 and 20.14 mosquitoes per light trap hour, respectively, with the highest density found in livestock pens, and the dominant species were Culex pipiens pallens, Aedes vexans, Ae. dorsalis and Anopheles sinensis. The fly densities were 14.93, 10.31 and 7.51 flies per cage-day, respectively, with the highest density found in the external environments of restaurants, and the dominant species were Lucilia sericata, Muscina stabulans and Musca domestica. The densities of Blattella germanica were 1.41, 1.05 and 0.94 cockroaches per glue trap, respectively, and the infestation rates were 36.97%, 25.75% and 22.82%, respectively, with the highest density and infestation rate found in hospitals and farmer markets. Conclusion The species compositions and densities of main vectors in Shenyang have been generally identified through a 3-year surveillance.