Rockfalls are exist universally in mountain regions, steep cliffs and rock slopes with a high risk of personal safety and severely destructive of property or infrastructures. The rock mass instability and different magnitude rockfalls frequency are closely related to the rock mass structural geometry character. With the development of three - dimension rockfall modeling algorithms and tools during the last decade, we could see more about bedrock failure mechanisms and rockfall frequency under the control of rockfall scars geometry. Based the three-dimensional real scene model data of UAV point cloud, block size, volumetric joint count, joints spacing and average length of joints are carried out with statistical analysis. In this paper, we discuss cumulative frequency relation of the block size, volumetric joint count, and joints spacing, found that the block size and the volumetric joint count are follow power law distribution, with the exponent b adjusted in the range of 0.5~0.9 and 0.4~0.6, respectively. We establish the relationship of rockfall scars structure with rockfall frequency, assess its suitability. The relation can be used as a preliminary method to estimate the rockfall frequency.