A river ecosystem is a treasure that is home to a wide variety of wetland species. The construction of bridges might have a deep impact on diversity of such an ecosystem. The ecological consequence of bridge abutments was studied by monitoring the benthic macroinvertebrate community at six main bridges on the Tuhai and Majia rivers in eastern China. We collected samples of macroinvertebrates from upstream to downstream during the summer hight-water period, and we monitored water quality at each site. The macroinvertebrate community of under-bridge sites was significantly correlated with that of reference sites in abundance, biomass, and richness. The benthic macroinvertebrate communities were not significantly different between under-bridge sites and reference sites in terms of abundance and biomass, while they were significantly different in terms of richness and the Shannon-Wiener index. This pattern outlined a major impact of bridge abutments on benthic macroinvertebrate communities for the first time, indicating the importance of habitat restoration after river construction was finished. Suitable measures should be taken to minimize the impact of bridge abutments.