The authors propose a maintenance management system for reinforced concrete subway tunnels to perform efficient maintenance management in view of preventive maintenance and repair of distressed concrete. The proposed system consists of three subsystems and has been put into trial use on an actual subway line. Based on the deterioration prediction using numerical models coupled with on-site measurement information, priorities, and timings are assigned to repair work based on the thresholds uniquely determined by the company, and maintenance management plans are created within imposed budget constraints. Through a couple of case studies on corrosion of reinforcing bars used for the actual structure, the proposed system is shown to be capable of predicting deterioration propagation almost approximately. Further, it is also demonstrated to be helpful to calculate maintenance management cost and to make an appropriate maintenance management plan under various repair strategies.