Abstract: In order to increase the portability for the risk assessment system of gas pipeline, based on GIS and XML and taking ArcGIS as a development platform, a gas pipeline risk evaluation system is established. The system is composed of pipeline database management, pipeline failure index dynamic management, risk assessment and statistical analysis. This system includes data input and output, query statistics, spatial analysis and other functions, can provide a semi-quantitative risk assessment based on as-built mathematical model of pipeline risk assessment, determine the risk class for the given zone pipeline, so as to provide the decision-making support to the risk alarm and establish accident emergency response plan.