Japan's ports were major hubs of the international maritime container transportation system. However their roles as hubs have been disappearing these days because of efficient ports of other countries in Asia with relatively cheaper port charges. Therefore, it is important for Japan to reduce the cost related with ports and improve port services so as to increase the cargo volume to be handled in ports. For this, we propose a public berth system where the ship-to-berth allocation is dynamically performed. In this parer we discuss the efficient berth allocation by using Genetic algorithm (GA) . We conduct some numerical experiments with ship arrival and handling data in port of Kobe, resulting in the same handling performance with fewer berths available than those in Kobe.