Abstract: The levels of concentration of endotoxin in water were reviewed, and the removal efficiencies of endotoxin by different water treatment processes were compared. According to the previous studies, the median concentrations of endotoxin in surface water, drinking water, secondary sewage effluent and tertiary effluent were 145, 20.5, 1440, 422 EU/mL, respectively. Secondary sewage effluent and tertiary effluent have relatively higher levels of endotoxin concentration. In the process of water treatment, coagulation and filtration can remove endotoxin while biological activated carbon process will result in the increase of endotoxin. Removal of endotoxin by chlorination or UV disinfection is instable, with the maximum removal efficiency of only about 20%. However, ozone disinfection is effective to remove endotoxin, with the maximum removal efficiency of 74%.