Japanese government has implemented a policy of “Strategic International Container Port” for integrating proximity ports to compete with Busan port. In 2014, Kobe and Osaka ports made a joint venture “Kobe-Osaka International Port Corporation” in line with the policy of Japanese government. The main purpose of establishing this corporation is integrated operation for strengthening their competitiveness. However, this company faces the difficulty of achieving the original purpose. In order to explore the effective management and operation of integrated port, this paper compares four actual cases of port integration from the view of involvement of state or central government, governance structure and complementarity of two ports. As a result, it is clarified that the involvement of Japanese government better to be changed in order to achieve effective management of integrated port.