Abstract: The environmental estrogen contamination is one of the important factors causing human reproductive dysfunction, dysplasia, cardiovascular disease and cancer. Activities of environmental estrogen are closely related to sex ratio and reproduction of wild animals. To monitor the discharges of environmental estrogens from wastewater treatment, we tested variations in estrogenic activity during treatment in four municipal wastewater treatment plants (WWTPs) and one reclaimed water plant in Dalian, Shenyang, Harbin and Tianjin by using a human estrogen receptor recombinant yeast assay. In addition, we evaluated the capabilities of secondary treatment for environmental estrogen removal in WWTPs and the reclaimed water plant as well as the capabilities of tertiary treatment in reclaimed water plant. The estrogen equivalent (EEQ) of the effluents from four WWTPs employing activated sludge and UV disinfection ranged from 0.5 to 1.5 ng L−1. After tertiary treatment process in the reclaimed water plant, estrogen activity of the effluent was below the method detection limit (0.02 ng L−1). The analysis results of the fractional components showed that the estrogenic activities of water samples were mainly caused by strong polar and weak polar components, and the estrogenic activities in the strong polar component increased after UV disinfection. The removal of environmental estrogen in the primary and activated sludge treatment processes of four WWTPs were in the range of 46%～81%, with removal ranging from 5.2% to 22% by UV disinfection process. The reductions in environmental estrogen by coagulation, microfiltration and reverse osmosis were 63%, 16% and 98% in the reclaimed water plant. The results of the present study suggested that the discharging effluents from activated sludge treatment would result in pollution of environmental estrogens to some extent, whereas tertiary treatment is effective to improve the removal of these pollutants.