For this study, we investigated slope stability and tree shape in two study plots of Japanese cedar plantation forest in an area with numerous collapses, in order to clarify the relationship between tree shape type and slope stability. To assess the tree shape objectively, we used 3D point cloud data obtained using ground laser scanning. Slope stability was assessed using the safety factor formula. Results show that, on a plot where the overall safety factor is low, trees with leaning stems can be found in the low safety factor area. Particularly, trees with bent stems were concentrated near the collapse. On another plot, which is a slope that includes the valley head, even though the overall safety factor is high, some leaning stem trees exist in areas where the valley head and numerous collapses occur. These findings suggest that slope stability characteristics can be inferred from differences in the distributions of standing trees classified by tree shape.