It presents to development the first phase research begun in 2016 about the indexing methodology application in the Rui de Barbosa Literary work. Describe the systematized vocabulary establishment for the representation of Casa de Rui Barbosa Foundation bibliographical collections, cause theoretical foundations don´t improve the information elaboration process and retrieval therefore this study propose the Concept theory methodological by Ingetraut Dahlberg (1978) to solve this problem. Its purpose is deepen the foundation theoretical of the information representation process coming from the bibliographical collections. The methodology proposes to identify concepts, based on the study of the indexation methodology that is based on Concept Theory. It concludes that indexing is a practice that needs to be systematically discussed, reviewed and improved.