Abstract: Because of complexity and uncertainty of landslides and limitations of prediction theory at present, it is very difficult to forecast landslides in time. This paper presents a GIS-based comprehensive landslide forecasting information system. Based on the GIS platform, the system combines quantitative forecasting based on the landslide monitoring data with qualitative forecasting on the basis of experts experience and knowledge, using an intelligent decision-making support system to make full use of knowledge base. The deformation and failure mechanisms, stability condition and failure probability of landslides can be assessed from this comprehensive system. In addition, the deformation stage and sliding time can also be predicted. Therefore, it provides useful information on landslide forecasting for decision making.