Abstract: As a superficial failure mode of slope especially high and steep slope,rock falls is one of the severe geological disasters.It is always the emphasis in slope engineering investigation for its characteristics of sudden occurrence,fast speed and violent power.Due to the dangerous rock masses triggering rock falls disasters mostly scatter at top of high and steep slopes and it will cost huge manpower and material resources with the attempt to manage the disasters totally there,it mostly adopts rockfalls prevention solutions before rockfalls causing disaster now.After some proper simplification in theory based on practical situation,this paper applies kinematics into some typical Rock falls disaster in Slope Engineering Investigation along a road to calculate and analyze the motion trail of rock falls,likes rock falls velocity,bounce height,displacement and kinetic energy.As a result,rock falls could cover the road with a serious impact on the normal operation of road and pedestrians safety.It is suggested that SNS flexible active protection net should be adopted to prevent rock falls and provides specific fixed locations and relevant parameters.