Direct disposal of dredged sediments in landfill sites may possess potential ecological risks to environment as they are abundant in contaminant. An experiment was conducted to analysis the concentrations and potential ecological risks of different contaminants including heavy metals, polycyclic aromatic hydrocarbons(PAHs) and polychlorinated biphenyls(PCBs) in dredged sediment landfill sites in Lake Taihu and Lake Chaohu in China. According to the potential ecological risk assessments of heavy metals and risk quotients of persistent organic pollutants, the potential ecological risks of different contaminants were quantified. Results illustrate that potential ecological risks of dredged sediments are relatively low in landfill sites in Lake Taihu, while are considerable in Lake Chaohu. In addition, the high accumulations of PCBs in dredged sediments possess high potential ecological risks to environment, and need more attention from managers.