The world-famous Three Gorges Project (TGP) is the largest hydropower station in the world and also the largest water resources and hydropower project constructed in China. The impoundment of Three Gorges Reservoir reached the design water level of 175 m for the first time on October 26, 2010, which marked that the various functions such as flood control, power generation and navigation of TGP can meet the design requirements. It took nearly 100 years from conception, demonstration, design, construction and operation to final completion of TGP. How was the conception of TGP proposed? What a role it should be? What are different opinions existed? How was the project demonstrated? What was the conclusion of demonstration? Those are the issues that many people care about but do not quite understand. A compendious introduction is made in memory of the achievement of the century dream.