Sea ports and the port environment are a key subsystem of the maritime and state transport system. They participate in the development of the port activities and in the other supporting economic activities that affect on the development of local, regional and national economy. In terms of globalization, liberalization, privatization, restructuring, information technology, and the port`s monopolist position in the mass transport of cargo, seaports need to adapt to the modern business conditions to remain competitive in the global market. Today, the largest and the most efficient seaports in the world are still a public, but only a few of them are still managed by public sector. In inability to achieve the higher stage of development process ports are turned to the private sector as partners in financing and management for several reasons; need to improve operational efficiency and increase service capacity, to modernize and improve the level of port services, and finally to insure investment requirements that are outside financial and managerial capabilities of public port authorities. The current situation in the Croatian seaports is unsatisfactory. The limited accesses to sources of long-term financing and insufficient own resources for finance major capital investments are resulting in delayed development of certain Croatian ports. The legal framework still does not resolve the complex issues of the capital investment in the public maritime domain and still has not established a comprehensive, clear and transparent governance integrated model for managing issues in the public maritime domain. Government subsidies, that are unsustainable and lack of transparency in setting priorities for the seaports development, results in impulsive control without the theoretical and scientific support, as well as practical application of the relevant factors of growth and the development. The sustainability of access to finance public-private partnership in the system of seaports is not purpose by itself. The need for better business operation requires a partner who will be able to meet three key conditions: the achievement of port operations efficiency at the world level, price competition against the Northern and Mediterranean ports and the quality of port services on the global level. For these reasons, need for deliberation on the development of the Croatian seaport system on the principals of public - private partnerships is neccesery. General model of development is based on systematic approach, generation of possible scenarios depending on the degree of private partner involvement (the status quo, minimal and maximum participation), the selection criteria for evaluating those who contribute to the development and evaluation of certain stakeholders: government sector, private sector and civil society. In doctoral dissertation The Multi-Act Multi-Criteria Analysis (MAMCA) in the case of the port of Rijeka was applied, that is based on the optimization and ranking of scenarios according to specific goals, research problem, criteria and opinions of stakeholders. Select the appropriate scenario development and implementation of the public-private partnership is based on certain assumptions and includes numerous activities related to the preparation, implementation and control models. The success of the implementation of public - private partnerships can be measured by the actual economic effects, such as creating better conditions for development of port activities, greater availability of long-term sources of finance, budget relieving the public (local) institutions, development of local, regional and national economy.