Abstract: The system of aquatic environment standards and its enforcement in USA is consisted of ambient water quality standards and effluent limitations or standards. USEPA focused on the practicability of the standards in setting them. The two kinds of standards are set to complement each other in functions. In enforcement, aquatic environment standards are not acting in isolation, but together with legal systems such as permit system and market organisms such as permit trading. Through the above way, the aquatic environment standards and its enforcement make up a complete system. We can draw on the experience of USA in setting and enforcing of aquatic environment standards in China.