Abstract: A structural rock mass is developed at the underpart of Qingshiliang ridge which stands at right bank of upstream of dam. Stability of the structural rock mass directly affects safety of construction and run of hydropower station infall. Based on engineering geological conditions of structural rock mass and its periphery, the paper takes measure of limit equilibrium to compute the stability of the rock mass. Computed value indicates that stability against sliding is on the low side under conditions of special load combination of earthquake and deadweight, so measures must be taken to reinforce the structural rock mass. Some deep and superficial reinforcement measures such as anchorage, anchor, anchor rod pile and concrete clung to the slope, and so on, are considered to strengthen stability of structural rock mass, of which anchorage is to improve monolithic stability and anchor, concrete clung to the slope to local stability according to superficial slope falling-sliding failure mode. Finally, monitoring system is set on the surface of structural rock mass and its periphery slope. Stability of reinforced structural rock mass can meet design demand by computing.