In developing cooperative relations with ASEAN, Japan certainly has its own interest, both politically and economically. Japan’s need of energy resources like oil, natural gas, and coal cannot be fulfill by its own nation, therefore Japan needs other nations in order to complete the needs of natural resources. With the high cost of productivity within the nation such as labor resources, and natural resources lead Japan to do investments in other countries so they will be able to do the production in order to fulfill the needs. This research is supported by Liberalism Theory and concepts such as, Globalization, International Business, Bilateral Cooperation, and Investment. However the methods those are using description analysis with qualitative and quantitative approach. Gathering data technique used literature, interviewing and websites. This research emphasized us that there’s Japan main interest’s in having relationship cooperation with ASEAN or what they called AJCEP. One of the Japan’s interest in having relationship with AJCEP is as the stepping stone to improved the economic corporation with ASEAN, because Japan Economic indirectly related with economic around this area. ASEAN is also the main resources for Japan to fulfill their industrial needs. Additionally, ASEAN is a very big market demand for Japan. Japan is very supportive to create a very political stability and safety in ASEAN. This is due to the close economic relationship between ASEAN and Japan. So that, if there is political and security instability in the ASEAN region, it will also disrupt the stability of the Japan’s economy indirectly.