For the fourth time since 1964, seismologists and other geophysicists from Japan and the United States met to discuss in detail the past progress, current status, and future outlook of the programs of research on earthquake prediction and control in each of the two nations. The seminar, held in Boulder, Colorado, August 13–15, was an activity within the U.S.-Japan Cooperative Science Program and was jointly sponsored by the Japan Society for the Promotion of Science and the NSF. Eleven Japanese delegates and observers, representing 8 different research institutes and agencies, joined 28 American participants from 17 universities and government agencies for the seminar. The program consisted of 42 formal presentations and two discussion sessions. In this report we give a summary of the proceedings of the seminar. The abstracts of the papers presented are available on microfiche from the American Geophysical Union.