Having a port and port facilities are not only important prerequisite when it comes to developing trade and economic activity in a maritime country, but also for the world economy. The goal of every maritime country is to acquire higher economic growth and impact in the segments of ports and port facilities and to optimally harmonize their development and management. An example is the Republic of Croatia, a maritime country with its great potential in using ports and port facilities as one of its important economic activities. Croatia has an enormous impact in this process, because with the use of different programs, economic measures and adequate legal solutions it can either stimulate or hinder the development of the overall port system. The Croatian port system, along with its development, is constrained with a number of factors. Every one of these factors has some kind of impact on the development of the overall port system, and only with the harmonized cooperation of the factors an optimal development leading to expansions of the ports, cities and regions can be achieved. This thesis deals with the port system features and their development, with emphasis on the developmental conception of the Croatian port system, and the analysis of the existing situation in certain ports in the Republic of Croatia.