A partitioned signature file is an enhancement of the signature file that divides all the signatures into blocks in such a way that each block contains the signatures with the same key. Its directory storesall the keys as meta information for avoiding unnecessary block accesses by examming them first before the acture searching of the blocks.. Efficient directory management is very important in large databasse environments since ist size gets larger proportionally to that of the database. In this paper, we first point out the problems in the directory management methods of the previous partitioned signature files, and then present a new one solving them. OUr method offers good features in the followint three aspects: (1) suitability for large database environments, (2) adaptability to dynamic situations, and (3) storage overhead for the directory. Moreover, we can seamlessly integrate it as a subcomponent into previously-developed general-purpose storage engines. These features show that our method is applicableto signature-based access structures for the content-based retrieval in various multimedia applications such as hypermedia systems, digital library systems, multimedia document systems, multimedia mailing systems, and so on.