This study aims to evaluate the quality of CD-ROM databases: Korean MARC on Disc and Korean National Bibliographies on CD-ROM. The five criteria(accuracy, completeness, consistency on the quality of data itself and ease of use, variety of retrieval function on the quality of database services) are used to measure their quality. The purpose of this study was to diagnose the quality of two CD-ROM databases mentioned above and to analyses the measured result of quality comparatively and to find out the problems of them and also to provide possible suggestions for their improvements.