Abstract: The seismic fragility of a RC (reinforced concrete) continuous girder bridge is analyzed, with consideration of damages of bridge piers, bearing components and the collision of the main beam. In view of the structural parameter randomness of the bridge structure, 20 near-fault ground motions are selected from the PEER(Paciflc Earthquake Engineering Research database), and a large number of random structure samples are established. Using the bridge damage index under difierent damage states, the fragility curves of the bridge components and the bridge system are obtained based on the structure of the capacity and the demand. According to the actual seismic demand of similar as-built bridges, the damage states can be obtained in the sense of probability, and provide a reference for future seismic damage predictions.