Experimental petrology has now spread throughout Japan. New, exciting high-pressure petrology experiments, with innovative instruments that have names like “MAX-80,” “MASS,” and the “Photon Factory,” are being conducted at more than 20 Japanese laboratories. The purpose of the experiments has been to map out the research area encompassing conditions that duplicate those of the earth's upper mantle, extending through the transition zone (1 bar-225 kbar, or 0.0001-22.5 GPa). The experimental techniques in these studies are second in importance only to the broad and extensive scientific issues. There are numerous efforts to determine phase relations, melting phenomena, calorimetric values, and elastic properties of mantle mineral assemblages at the corresponding pressures and temperatures. The results of these efforts were in considerable evidence at the recent U.S.-Japan conference on High-Pressure Research Applications in Geophysics and Geochemistry, which was held in Kahuku, Hawaii, January 13–16, 1986. Papers in experimental petrology were presented by researchers from 12 Japanese universities and nine Japanese national research institutes, and from 11 U.S. universities, three U.S. National Laboratories. In addition, papers were presented by researchers from individual universities in Australia, Canada, and West Germany.