The Port Development has been achieved by the Government because it needs large scale of funds. However, since 1994, the Govenment has been implemeting private investments for constructing and operating the ports and so on. Although the Government had high expectation that it could expedite the expansion of the port facilities, there were many problems in view of construction, management, financial and social environment. This study figure out that most of the important reasons are the uncertainty of risk allocation between private investors and the Government, using with Analytic Hierarchy Process. It is expected that the results of this study will encourage more private investors to participate in port private investments in the future.