This paper aims at clarifying reasons why IG Farben failed in selling the lisence of the IG method for synthetic oil through an analysis of documents held BASF Archive and other documents. In the middle of 1930 es IG Farben changed its starategy and decided to sell the lisence of the IG method for synthetic oil abroad as well as in Germany. Its first target was Japanese market. In those years it dominated in Japan a boom for synthetic oil industry. IG Farben made every effort and approached to South Manchurian Railway Company, Mitsubishi Mining Co., Ogura petroleum Co. and other 10 companies or projects. It could not, however, succeed in concluding any contract with them. There can be three hypotheses to explain IG's failure : (1) The International Hydrogeneration Engineering and Chemical Co., which was established by four big enterprises incuding IG and held the hydrogeneration patent, restrained IG's effort; (2) Strict conditions presented by IG Farben discouraged Japanese companies which intended to introduce the IG method; (3) Japanese Navy, which was trying to develop socalled Navy method for itself, opposed against introducing the IG method strongly. My analysis reveals : (1) In spite of IHEC's negative attitude IG had chances to conclude contracts with some Japanese companies till 1939; (2) There were some cases where Japanese side did not take presented conditions too strict; and (3) The Navy hindered effectively projects of some companies such as South Manchurian Railway Company and Ogura Petroleum Co. Results of my analysis abandon former two hypotheses, but do not abandon the last one.