Since the variety of engineering activities require excavation of rock slopes, it is of a great concern to civil, geotechnical and environmental engineers to assess instability of rock slope in order to prevent damages due to unexpected rock failure. This book presents some methods such as kinematic analysis, slope mass rating, stereographic projection in order to identify the type of failure and also to estimate probability of failure in rock slope. It is a useful book for engineers, researchers, undergraduate and postgraduate students in fields of geotechnic, rock mechanic, geology and mining.