Abstract: The method of dynamical numerical analysis is used to analyse the movement of grains on slope; and the research is based on in-situ observation and model tests. First, there are two main movement patterns, slide and roll. And these two movement patterns can converse each other. The movement can be caused by pull or push forces. On the pull-surface, most of grains move in rolling pattern and the roll will be driven by the movement of sands on the top or in front of them. On the push-surface, most of grains move in slide pattern and the slide will be driven from the top or back of them. Then, based on the driven force conditions of a grain of sand, the movement parameters and dynamical model of sand in sliding, rolling and crash are derived.

Key words: sand-sliding slope composed by granular clastics, movement characteristics, slide, roll, crash