According to the law of deformation of landslide, the grey forecast GM(1, 1) based on the site observing displacement is built up in this paper. And the forecast model for landslide is set up accoroding to the grey Verhulst model of the deforming rate. Accordingly, the deformation and deforming trend of future can be calculated, and the landslide can be forecasted, The theory, and色principle i of this method is expound,0 It is emphatically expounded that 父the optimization processing of data and the inspection and revision of the model, This文method is质:verified by landslide cases.