The purpose of this paper is to make clear relationship between an international cartel and a domestic cartel in Japan through examining the case of the “Six Companies Agreement” on gasoline of 1932. The member companies of this agreement were the Rising Sun Petroleum, the Socony-Vacuum Corporation, the Nippon Oil, the Ogura Oil, the Mitsubishi Oil, and the Mitsui & Company. The Rising Sun belonged to Anglo-Dutch Royal Dutch Shell Group, and the Socony-Vacuum was an American company. In those days, the Royal Dutch Shell concluded the international cartel agreement with the Socony-Vacuum. Of the rest four companies, the Nippon Oil, the Ogura Oil, and the Mitsui & Company were genuine Japanese companies, and the Mitsubishi Oil was a joint concern of the Mitsubishi in Japan and the Associated Oil in the United States of America.The commonly accepted theory emphasizes the superiority of the international cartel between the Royal Dutch Shell and the Socony-Vacuum to the domestic cartel, that is the “Six Companies Agreement” of 1932 in Japan. The conclusion of this paper, however, denies the commonly accepted theory. It may safely be said that the control power in the gasoline market of the international cartel was restricted within narrow limits in a “medium advanced country” like Japan.