Abstract: Based on the improvement of the existing predictive models,a predictive model for the seismic damage of transportation systems in mountain cities was established to reasonably predict the seismic damage.The improvement is mainly based on the characters of roads,landforms and buildings in mountain cities.In the improved model,road cell,bridge cell,side slope cell and tunnel cell are in series.Their failure correlation is considered,and the present model of predicting the debris distribution of collapsed buildings in the road cell is improved.The established model was applied to predict the seismic damage of the transportation system in the downtown of Chongqing City,and the relative evaluation of the connectivity reliability of the road networks in the downtown under different seismic intensities was given.