This paper gives detailed analysis and summary to the weathering and erosion process of rock slope,discovery the weathering velocity of rock slope is mainly controlled by such factors as lithology,structures,climate,structural characteristics of rock mass,the undulation and exposed area of rock surface,and man-made factor,furthermore,analysis the eroding mechanism of rock slope and its influencing factors.The result shows that the strength of rock evidently reduces with the increase of number of freezing and thawing cycle.These will be provided some valuable references to control the weathering and erosion of rock slope in engineering.