Abstract: The Yellow River Xiaolangdi Project is characterizedby large scale, important geographic location, complicated geologicalconditions, strict operational requirements and unique water and sediment regime, thus becomes one of the most challenging water projectsin the world. The technical complexity of the project is mainly due toits complicated geological conditions and high sediment concentration ofthe Yellow River flow. Major technical problems have been solved in thefields of soil mechanics and soil dynamics, rock mechanics, structuralmechanics and structural dynamics and water engineering hydraulics,and have also pushed forward the development of the testing and analysismethods in engineering mechanics.