This volume contains the 17 research papers presented at the first International Working Conference on Co- operating Knowledge Based Systems, held at the University of Keele, from 3-5 October 1990. This was the first international conference aimed at bringing together the distributed database (DDB) and distributed AI (DAI) experts, from both academia and industry, to discuss the issues of the next generation of knowledge based systems, namely Cooperating Knowledge Based Systems (CKBS). The organisers hoped that the presence of both database and AI researchers would help to bring about a synthesis of ideas for fruitful industrial applications. As the area of CKBS is new, the conference was planned as an 'ideas conference', where interesting new ideas, rather than results from completed projects, were explored, discussed, and debated. In order to provide a conductive atmosphere for in-depth discussions, attendance at the conference was restricted to those who have a genuine interest in this new area - even then, there were over 80 participants from 15 countries. To facilitate discussion, the conference was residential, and plenty of time was allowed after each presentation for discussion, in which both DDB and DAI researchers participated. These discussions were taped and selected transcripts are included in this book, following each paper. There were over 80 extended abstracts submitted, of which less than half were selected by the Programme Committee for presentation. Following the conference, a second review was carried out, this time on full papers, from which the 17 papers were selected for publication in this book. It is hoped that each paper will be of interest to both of the research communities. The papers are grouped under six headings: Cooperation Framework - DB Perspectives; Cooperation Framework - AI Perspectives; Conflict Resolution Strategy; Knowledge Revision; Multi-agent Development Models; Interaction in Data/Knowledge Bases.