High rock slopes are a kind of very common geological bodies to be being the environment or bearing layers of engineering structures in southwestern China. They show some distinguished characteristics being different from general rock slopes because of the special geological background in this area. According to the data from a lot of field investigation, they can be characterized as super height, high geostress and complicated deformation and failure evolution process. The author gives an index called as over high ratio to describe the environment effect from the slope height. A theoretical geostress distribution model in deep valley is established, which reveals the “hump” pattern of geostress in high rock slopes. From the view of dynamic mechanism, a three-stage model is suggested to describe the dynamic evolution process such as epigenetic recreation, time-dependent deformation and failure. Furthermore, the author gives out the transferring conditions of different stages and basic laws of vertical classification of dynamic process development in deep valleys.