The purpose of this study is to research and analyse the end user's satisfactions concerning the architecture, design, format, terminology, query formulation, hits, that is, the primary factors of the search mechanism in digital libraries. and then, to present its improvements. The search mechanism of National Digital Library in Korea is decided as the sample, and the 80 students who majored in the library and information science are selected as subjects. The end user's satisfactions are measured by questionnaire.