This chapter introduces major landslide causes and triggers and outlines the principles of slope stability analysis for rock mass. It discusses the slope stability at the project site with considerations of different ground water conditions. Depending on the type of motion, slope failures in rock mass can be classified as rock topples, rock slide and rock spread. Slope stability analysis is a procedure that engineers employ to assess the stability of natural and man-made slopes. Many failures occur on slopes where heavily weathered rocks are underlain by hard bedrock. The effect of ground water on the slope stability can be investigated as well. The effect of rock strength on slope stability can be seen when the cohesion of rock material significantly decreases, making the slope less stable. The main concepts of stabilization techniques are to prevent water from going in the slope and increasing the rock strength by means of anchors.