The purpose of this study was to develope a group of metrics that would document effects of pollution on benthic macroinvertebrate assemblages for biocriteria a nd assessment in the Qinhuai River. Benthic macroinvertebrates as semblages were collected from 21 sites with a D-frame net in Qin huai River, Jiangsu province from 1999~2001. Nine upstream sites were considered in reference condition and 12 down stream sites were considered impaired. Twel ve metrics: total number of taxa, ET taxa, %Ephemeroptera, %...