Abstract: The situation of Whole Effluent Toxicity (WET) development history and relevant government documents published in the United States were briefly introduced. The application methods of WET for water toxics control in the United States were discussed in details, including defining water quality criteria and standards for WET, characterizing effluent thus evaluating reasonable potential to cause or contribute to an excursion above water quality criteria or standards, calculating WET permit limits, conducting Toxicity Reduction Evaluation (TRE) and so on. For all these works, the United States have established scientific methodology. It presents important reference meanings for water toxics control and management in China, including clarifying the importance of discharging permits and thus improving the regulation systems of water pollutants control and management, establishing water quality-based pollutants control and management systems and methodologies, strengthening WET monitoring and setting up methodologies of toxics control using WET.