Abstract: The downslope movement of detached rock blocks along steep slopes is an important process endangering the safety of the infrastructures along the slope foot and on the valley bottom. The complexity of rockfll movement is determined by several external and internal factors. But only limited knowledge is available on the influence of various factors on the velocity and distance of movement of such blocks. The factors the kinematic properties and energy conversions of rockfalls are studied. Through theoretical comparison and analysis, the main parameters for the trajectories of the rockfalls are selected (coefficient of restitution, friction angle of slope, slope roughness, angular velocity of rotation and rolling motion) for numerical simulations and model tests. The results may help us determine the corresponding engineering protection measures.