An assessment of spatiotemporal variations of water quality and benthos community in Suzhou Creek was conducted based on long-term data (1996-2006). The results showed that the clean up projects did not change low DO situation of downstream. Benthos community change indicated ecological deterioration on the upstream, which might offset restoration efforts on the downstream. The upstream area of Suzhou Creek should be the priority in ecological restoration. Long-term data analysis is considered an effective tool of water quality and ecological assessment, not only in interpreting the distribution of biological data coupled with water quality parameters， but also in revealing the critical river segment for ecological restoration.