Abstract: An approach by integrating multi-view aerial imagery and LiDAR data is proposed for automatically reconstructing 3D building models with precise geometric position and details. It consists of three main steps: building boundary extraction, 3D boundary determination and 3D building model reconstruction. Two new algorithms are proposed: (1) a method on 3D building boundary determination by integrating multi-view 2D boundaries and LiDAR data; (2) an improved split-merge-shape algorithm based on LiDAR data. The results demonstrated that the complex buildings can be reconstructed well by the proposed approach; comparing the approach only using LiDAR data, the constructed 3D models have higher correctness and completeness and have more accurate geometric position.