Abstract
　There have been a great number of human casualties caused by rapid landslides. Prediction of rapid landslides is, therefore, strongly desired by society. Several case studies of rapid landslides are reviewed from the view point of their symptoms. If natural slopes are observed carefully, some symptoms of rapid landslides may be found, and their prediction becomes possible. As it is impossible to observe all slopes, assignment of the most dangerous slopes is neccessary. The technical methods that make the assignment of dangerous slopes possible are reviewed. Critical levels of rainfall and melting water must be determined in order to predict the timing of landslides as accurately as that of debris-slides in weathered granites．

*信州大学工学部
Faculty of Engineering, Shinshu University