Proceeding of the Joint International Symposium on Deformatuon Monitoring. 2-4 November, 2011. Hong Kong. China. Report. Laser scanning considers as an efficient tool for measuring large amount of points on specific surface within short time. It obviously is an effective tool for deformation detection between two scanned results with same surface. A study for two laser scanning results between two stages in a tunnel construction project will be presented in this paper. The tracing of major and minor change of terrain were based on a large amount of data with special filtering technique mentioned in this paper.