Pesticides are wildly used in agricultural production in China. The use of pesticides affects the environment significantly. Pesticides are introduced to the aquatic ecosystem in a variety of ways such as, leaching, evaporation and precipitation cycles, surface runoff etc. Chinese manufacturers produce a large amount of pesticides every year. Technical material production accounts for about 60% of global production capacity. This article will briefly introduce assessment of risk to aquatic ecosystems in China. Pesticide registration in China is based on tiered assessment whereby increased production volume incurs increased regulatory compliance requirements including the evaluation of pesticide impact to aquatic ecosystems. If primary evaluation is unacceptable, senior assessment is necessary. Environmental risk assessment consists of: