原文提要:本文概括介绍了日本科学技术情报中心为取代目前正在服务的 JOIS-Ⅱ联机情报检索系统而开发的、预定在1990年1月投入服务的 JOIS-Ⅲ重系统。JOIS-Ⅲ是一个旨在扩充检索功能、充实数据库和高速处理大量数据等方面对 JOIS-Ⅱ进行全面改进的检索系统。另外本文还讨论了诸如用于大型数据库的位标记结构和系列结构等检索对象文档的结构问题。 This article gives an overview of the JOIS-III heavy system scheduled to be operational in January 1990 by the Japan Science and Technology Information Center to replace the JOIS-II online intelligence retrieval system currently in service. JOIS-III is a retrieval system that aims to improve JOIS-II comprehensively in terms of expanding the search function, enriching the database and processing large amounts of data at high speed. In addition, this article also discusses the structural issues such as bitmap structure and series structure for large databases such as the search object document structure.