Monitoring as-built condition of existing building is required for efficient building operation and maintenance. To acquire the as-built data, terrestrial laser scanner has been widely used due to its fast speed and accuracy. However, conventional static laser scanning system has some restrictions of its operability for complex indoor environments because surveyors need to change scanner locations and register each scanned point cloud into a single data set in the post processing step. As an alternative, this study proposed a kinematic laser scanning system which continuously scans and registers the point cloud data using Simultaneous localization and mapping (SLAM) technique. The system was developed with two 2D laser range finders, and the experimental result showed the potential for mapping 3D indoor environment.