This paper reviews various aspects of authouity control system and presents prerequistes for an effective authority control in our future cooperative cataloging. It can be summarized as follows. First, numerous factors affecting authority control must be analyzed and consistent procedures and policies on the authority control have to be established. Second, to make an effective bibiographic data base there must be a standard for the information processing and a systematic organization for information sharing and communicating. Third, for this objective we have to build a MARC format, establish a network for the exchange of automatic authority records among systems, standardize the transcription of multscripts, and establish a centralized automatic authority system for a consistent maintenance of authorityrecords of the union data base. Fourth, it would be one of the best way of achieving cooperative cataloging to set up such a nation-wide authority control system as the NACO in Japan.