Yarlung Tsangbo Grand Canyon in southeastern Tibet of China possesses very abundant hydropower resources, where future hydropower development is of strategic importance to meet domestic energy demand and response climate warming,but may adversely affect the slope stability of the canyon. Field investigations indicate that bedrock incision of river bed prompted too many avalanches,landslides and debris flow occurring frequently in the canyon. The interaction between huge flow energy and riverbed structures (e. g. cascades and step-pool system) maintains the weak critical balance to hold the stability of the canyon. Two hydropower development schemes which include several steps hydropower plants and long distance diversion tunnels may have direct adverse effects on the canyon stability. Only fully understanding the impact of future hydropower development on the slope stability of the canyon,the adverse effects of the hydropower projects can be reduced to a minimum.