Abstract: This article presents a method for the seismic vulnerability analysis of RC piers, which predicts the damage levels of RC piers by using vector-valued intensity measures (IM). An urban bridge is taken as the analysis model. Considering the uncertainties of the bridge and ground motions, seismic vulnerability analysis of the RC pier is performed using vector-valued IM. Then, fragility surfaces of the RC pier for different damage states are studied. The research results indicate that, taking into account the complexity of the seismic excitation, the scalar IM tends to neglect some important characteristics of ground motion when conducting the seismic vulnerability analysis of the RC pier. However, vector-valued IM contains more ground motion information and it can reduce the dispersion in the prediction of damage levels of the RC pier effectively, which will be very important in seismic analysis. Compared with the fragility curves formed using scalar IM, the fragility surfaces deduced from vector-valued IM can better reflect the variability of the vulnerability failure probability of the RC pier caused by the second intensity measure parameter. Thus, when vector-valued IM is used in the seismic vulnerability analysis of the RC pier, it can more accurately evaluate the seismic performance of the RC pier.