There are multiple processes of damage with a lot of damage factors in existing concrete bridges in service. Although it is very difficult to define such damage processes quantitatively, it can be assumed that the bridge engineers who deal with bridge repair works have their own concepts of bridge rating system in their minds based on past engineering experiences and knowledges. In this paper, it has been proposed a global hierarchy model of damage factors for concrete bridges based on the Fuzzy Hierarchy Structural Modeling. Since the knowledges about the relation with damage factors were picked out through a questionnaire to a few experts, subjective uncertainties were included in the results. In order to deal with such uncertainties, the concepts of basic probability according to the Dempster & Shafer theory were applied. The final hierarchy model was selected from among several models in the viewpoint of simplicity and relation to available literature. This hierarchy model can be effectively utilized into the bridge rating system.
