Myanmar，as an ASEAN member，is a country with large territory and population and abundant resources. Since the end of WWII，Japan has maintained economic and political ties with Myanmar. Even during the period of Myanmar’s military government，when Myanmar was under the sanction of major western countries，Japan kept the economic diplomacy towards Myanmar through civilian economic assistance. Since Myanmar started its democratic reform in 2005 and Aung San SuuKyi took office in 2015，Japan，taking it as an opportunity to expand its influence，has made great effort in improving the economic relations with Myanmar，reflecting its pursuit of resource，energy and market and the consideration of cooperation with U.S. and containment against China.