Monitoring plays an important role in the informationbased construction of tunnels. A forecasting information system is established on basis of field data collection, analysis and feedback so as to scientifically forecast the main disasters in the tunnel construction. Taking the shallowburied asymmetricallyloaded portal section (on Gelong side) of the left tube of Jibai tunnel of GelongDuyun section of XiamenChengdu expressway as the study object, the authors successfully forecast the slope slide tendency in the tunnel portal section on basis of the monitoring results (convergence, displacement, crown settlement, ground surface displacement, etc.) and the forecasting information system. Therefore, the design and construction organization plan of the tunnel are adjusted, the risk are effectively controlled and the tunneling safety are guaranteed.