Abstract
A national library, as a repository of the bibliographical production of the country, has the obligation of controlling (acquiring and keeping) the exemplars of all the nation's publications. At the same time, it must work as a library-deposit, apart from producing a national bibliography and acting as a national center of bibliographical information. Unfortunately very few libraries in the world keep up with these purposes. In this environment, the National Library of Mexico, thanks to the bonds established with the high administration of the country, can count with the necessary resources to decorously carry out its functions. In this sense, it is very useful to interchange opinions for the better working of the National Library at the annual reunions of the CNLD (Conference of National Libraries Directors'), of worldly character, as well as the ABINIA (Assembly of the Association of Latin American National Libraries).