People pay attention to not only the state assessment of ecological security based on P-S-R (Pressure-State-Response) in practice, but also the future disaster trend problem. Disasters are caused by taking risks. Where there is hidden danger, there is also risk of a disaster. Ecological security dangers are factors of disaster. Ecological security disaster risk is the probability of deterioration and disaster which the ecological security state receives, as a result of the hidden danger harm to the compound eco-system in a certain areas, and it is the deterioration trend of ecological security state that people do not truly control or like to accept. This article applies the geography information system (GIS) analysis technique and ecological risk assessment method, according to the harm of regional paroxysmal and gradual dangers, study the theories and methods which related to the disaster trend (risk) based on the case study of Liaohe River.