Abstract: Significant changes occour in physical habitat of the middle and lower reaches of Yangtze River after impoundment of Three Gorges Reservoir, affecting the river function. Changes in typical physical habitats and its effect were analyzed. Researches should be strengthened were pointed out: ① In terms of monitoring: systematic and long-term monitoring, and monitoring of the effectiveness of river (waterway) management projects and ecological regulation. ② In terms of laws and mechanisms: mechanisms and commonalities of river morphology; mechanisms of vegetation change in the main stream and shoals, and the response laws and thresholds of flood levels and benthic animals to physical habitat changes. ③ In terms of methods and countermeasures: medium and long-term change prediction of hydrological conditions under the influence of multiple factors, channel regulation technology that adapts to changes in physical habitat and meets the demand, reservoir operation scheme that meet the objectives of water supply, benthic, fish breeding. Moreover, the integrated research of physical habitat change, impact, improvement strategy and technology needs to pay much more attention.

Key words: Three Gorges Reservoir, physical habitat, change, river morphology, hydrobiont