Abstract: Recently a series of systematic studies on water quality criteria (WQC) were conducted in China. Screening of test organisms is important for development of WQC. Annelids and aquatic insects are major components of the benthic ecosystem, and indispensable test organisms for derivation of WQC. According to the water quality criteria derivation guidelines of the US EPA, toxicity data of ten species of Annelids and aquatic insects widely distributed in China were collected and screened. A list of three most toxic pollutants to the organism was obtained through data analysis. The species sensitivities of these pollutants were analyzed through species sensitivity ranking. According to the species sensitivity distribution of the pollutants, the species could be regarded as test organisms of criteria, when their cumulative probabilities were less than 30%, The results showed that the species sensitivities were different when exposed to various pollutants. Tubifex tubifex were most sensitive to organotin compounds and copper; Branchiura sowerbyi were most sensitive to heavy metals; Nais sp.,Brachythemis contaminate, Baetis rhodani and Heptagenia sulphurea were most sensitive to pesticides; Dero sp. Were most sentive to surfactant and some heavy metals. In conclusion, Tubifex, Branchiura, Dero, Nais, Brachythemis, Baetis and Heptagenia could are ideal species of Annelids and aquatic insects in WQC studies.