The purpose of this study is to present basic data in order to improve the efficiency and the objectivity of diagnosing educational structures built with the reinforced concrete. For achieving the purpose, this paper, firstly, researches damage aspects of 22 public educational of facilities in Seoul, and summarizes the results of that research. Through the analysis and the evaluation of damage aspects, this paper shows the conclusions as follows; (1) Main damage to reduce structural capacities of building is the differential settlement. (2) Though the steel corrosion is occurred by several factors, the main cause is the faulty construction. (3) To prevent the damage development, a proper repair strategy is very important.