his paper examines three huge rockslides triggered by reservoir in the world They are the Vaint landslide in Italy, the Tangyanguang landslide in Hunan province of China and the Qianjiangping landslide in Three Gorges Reservoir of Central China. They have many similarities in geological conditions, triggering mechanism and deformation characteristics. The paper finds that the reservoir water flouting, slip surface soak softening and their coupling are the triggering causes. The paper proposes a landslide space prediction model. It is based on the geological structure included the following six essential factors: bedding slope structure, chair shape slope, soft inter-layers, slide out space, soft intercalation exposure at the toe, and deep and thick weathered rock mass. with the former four factors are the necessary conditions and the later two are selective. The main landslide deformation characteristics for short term are the formation of discontinued tensile cracks at the crown and the small collapse at the toe. The landslide deformation characteristics for near slide are the cracks at the crown continued and have closing tendency. The deep rockmass displacement orientation becomes upward. The creep v-t curve tangent is nearly upright. The creep speed is 20～30 cm per day.