Abstract: River terrain is the basic supporting data for river protection and utilization.The traditional surveying and mapping method of river terrain in mountainous areas has the disadvantages of high operational risk,high difficulty and low efficiency,and the aerial photogrammetric method cannot achieve high elevation accuracy and obtain ground information covered by vegetation.Featured by strong vegetation penetration,airborne LiDAR can solve the shortcomings of the aforementioned surveying and mapping methods combined with the advantages of image and laser point cloud.Terrain slope and vegetation coverage would affect the airborne LiDAR surveying and mapping accuracy of river terrain in mountainous areas compared with other work areas.In order to study the applicability of the airborne LiDAR method in surveying and mapping of river terrain in mountainous areas,this paper studied vegetation penetration and surveying accuracy of airborne LiDAR in typical mountain river areas according to terrain type and surface cover for the first time.The research showed:the plane accuracy of aerial image was better than that of laser point cloud,which could fully combine the advantages of high plane accuracy of image and high elevation accuracy of laser point cloud,and enriched the characterization approaches for surface information;airborne LiDAR had good vegetation penetration performance;the elevation accuracy of point cloud was affected by terrain slope and vegetation coverage,the steeper of slope and denser of vegetation,the lower accuracy was;the accuracy of the contour generated by point cloud without thinning was close to the accuracy of the point cloud.The results showed that airborne LiDAR could meet the requirements of large-scale river terrain and section accuracy in mountainous areas,and had good applicability for surveying and mapping of river terrains in mountainous areas.