For structures located in aggressive environments and earthquake regions, it is important to consider the effect of material corrosion on seismic performance. This chapter presents a seismic analysis methodology for corroded reinforced concrete (RC) bridges. It is shown that the analytical results are in good agreement with the experimental results regardless of the amount of steel corrosion. The proposed method is applied to lifetime seismic reliability analysis of corroded RC bridge piers, and the relationship between steel corrosion and seismic reliability is presented. After the occurrence of crack corrosion, seismic reliability of the pier is significantly reduced. If corrosion cracks in the bridge pier are detected by visual inspection, additional detailed inspections need to be performed.