Аннотация:Numerous historical large-scale rockslides are known in the Tien Shan mountains of Central Asia, most of them being caused by strong earthquakes, though aseismic failures have occurred there as well. Besides, several hundreds prehistoric mass movements of106-1010 m3 in volume have been identified throughout the entire mountain system. More than ten exceed 1 km3 in volume, and at least two have mobilised >10 km3 of rock. Thecombination of high local relief and slope steepness, complex geological structure withseveral active fault zones, and high seismic activity may be conducive to similarly largeevents in the future. However, the general absence on age constraints on most of thesecatastrophic failures, raises the problem of how to estimate the typical recurrence interval and geomorphic hazard from such destructive rock-slope failures. Slopes featuring evidences of ongoing creep-type deformations have been considered as sites of possible future rockslides, although such slope failures are most difficult to predict, and may occur at unexpected sites as well. Areas, where bedrock slope failures occur repeatedly per unit area and time, can be characterized by higher levels of susceptibility, and possibly, hazard. Any regional hazard assessment should ideally be based on the complete inventory of rockslides exceeding an arbitrary, yet practically necessary, threshold value, as well as on data on the magnitude and frequency of such rock-slope failures.