Abstract：The article introduces the historical background, the functioning and the key persons involved of the Three Gorges Project in the different period. Like all the other huge engineering project in the world, Three Gorges Project attracted lots of controversy ever since the beginning of the project. Especially in the late 1980's , when the project was in the re-verification, the ecological environment impact of the project became and will be the focus in the future. The positive and negative impacts of the Three Gorges Project on the ecological environment have been analyzed. The author thinks that the negative impacts of the hydropower projects are indistinct and sluggish. The biggest and most complicated ecological environment impacts of the Three Gorges Project are the sedimentation at the end of the reservoir and the scouring on the banks downstream the dam, which should be researched and observed in a long term and continuous way. The corresponding countermeasures for other negative impacts such as that on the geological environment, water environment, resettlement environment are also analyzed in the article.