The monitoring of construction for metro is an important procedure of guaranteeing construction safety and engineering quality, but the current monitoring data processing, analysis and transfer methods are unable to meet the need of safety management. Based on requirement investigation in metro companies, This paper puts forward a method with application of GIS software ArcGIS9.3. The functions of which such as map editing, data management, spatial analysis and three dimensional simulation carried on the analysis and processing can bc carried out to the subsidence data monitor for subway construction. It has been indicated in practice that new method provides the visual technical support and decision-making references vividly for the project managers and workers.