The DoD Basic Research Program is the cutting edge of the Defense Science and Technology Program. For more than 50 years, the Department of Defense has relied on its Basic Research Program to maintain U.S. military technological superiority. This objective has been realized primarily by DoD support for research into scientific and engineering areas of proven or potential importance to defense. DoD researchers also keep a watchful eye on research activities all over the world to prevent technological surprise. As the pace of technology quickens, it has become ever more important to maintain the world-class quality of the DoD research program, and to guide, coordinate, and integrate its many diverse activities. The Basic Research Plan (BRP) presents a comprehensive and reasonably complete overview of the whole DoD research program, presents the rationale for it, outlines its contents and organization, tabulates the funding (by program element as well as by discipline), and concludes with a few examples of its extraordinary accomplishments. The bulk of the funding of the DoD research program supports 12 disciplinary areas, managed by 10 Strategic Planning Groups (SPGs). (Two pairs of related disciplines are grouped together under one SPG.) Each discipline is briefly described. Interdisciplinary research is encouraged and is specifically addressed under three program titles: Strategic Research Areas (SRAs), Multidisciplinary University Research Initiative (MURI), and Government-Industry Cooperative University Research Program (GICUR). The program also supports infrastructure through education and training in science and engineering, and university instrumentation under the Defense University Research Instrumentation Program (DURIP).