This grant supports an Information Center on High Tc Superconductivity whose primary service is a twice-monthly newsletter which contains lists of preprints in this very active research area. It also provides a short analysis section which highlights information in the preprint listings which is judged to be particularly important. Other current information on technological advances, meetings, requests for proposals is provided. The service is subscribed to by about 2500 researchers by mail or e-mail, and an additional 4000 visits are made per month to the Web site that the Information Center also supports. %%% This Information Center on High Tc Superconductivity helps researchers worldwide in the active area of high temperature superconductors keep abreast of the latest research results. The newsletter and Web site which are supported make the progress of research in the area of superconductivity more rapid and less expensive, by helping researchers avoid duplication of efforts, and keeping them up to date on the latest developments in their field of research. ***