In June 2015,President of The Republic of the Philippines Benigno S. Aquino III paid an official state visit to Japan, and held a meeting with prime minister of Japan Shinzo Abe. Both of the state leader declared that the relationship between the two countries has entered the stage of Strengthened Strategic Partnership1. This boost up in bilateral relations of Japan-Philippine in the recent year especially since 2010, as a respond of the growing tension produced by the advancement of China’s assertive actions in the South China Sea and East China Sea. Japan as a state need to fulfill its national Interest to secure it self from the threat in their own region, and also need to support the freedom of navigation in the South China Sea, because of its strategic importance for the security and economy of Japan. This paper will explain and analyze the reasons why Japan strengthen it strategic cooperation with the Philippines in 2015