Berthing control is one of the most important phase of ship control, and its automation is desired for a long time. Some approaches for centralistic control have already proposed, but the complexity of the control process makes it almost impossible to design and implement, . In the area of autonomous agent research, research for generating coherent, robust, useful, and adaptive autonomous agents is becoming increasingly active. In this paper, berthing system was modeled as a multi-agent system, which consists of multiple tugboat agents and one propeller agent. Modelling and implementation technique for Müller's three-layered autonomous agent is proposed. Implementation results show the independency of numbers of the agents in the multi-agent system produces robustness, extensiveness, flexibility of the system architecture.