To study the influence of dam removal on river ecological environment, the impacts of dam removal on hydrological regime, sediment transport, fluvial geomorphology, river water quality, habitat quality and biodiversity were introduced. Progress on the response relationship among river physical chemical characteristics and important ecological characteristics was summarized.The impact of dam removal on ecological environment has spatiotemporal complexity and each ecological factor influences each other. Hydrological regime change is the trigger of all ecological responses and sediment transport is found to be the key factor affecting the ecological environment. Considering the long-term continuous development and utilization of rivers, the study of sediment transport and release of sediment pollutants, the prediction of the spatiotemporal variation of river water quality after dam removal, and the analysis of the response relationship between ecosystems at the watershed scale are important in the evaluation and decision-making of dam removal.