Objective To investigate the population composition, infestations and seasonal dynamics of cockroaches in Danyang so as to provide basis for scientific prevention and control of cockroaches. Methods During May 2008 to December 2015, 5 types of farmer produce markets, restaurants, hotels, hospitals and residential areas were chosen for investigation. The density of cockroaches was monitored by sticky-trap method once a month, and the captured cockroaches were then identified and counted. Excel 2007 and SPSS 18.0 softwares were used to collate and analyze the data. Chi square test and ranks test were used to compare the rate and density. Results In total, 26 928 cockroaches were caught during May 2008 to December 2015. The average infestation rate was 21.50%, and the average density was 2.47 individuals per trap. The average density and infestation rate of farm produce markets and restaurants were higher than other habitats with predominant species of Blattella germanica, accounting for 99.97%. The cockroach density exhibited one peak from September to October. Conclusion For nearly 8 years, the overall density of cockroaches in Danyang decreased first and then increased. Comprehensive measures for prevention and control should be taken, and a long-term mechanism should be established to control the cockroaches at a level below nuisance. The farm produce markets and restaurants should be the focus of prevention and control.