The purpose of this study is to develop a port simulation program for Inchon Port. The arrival and departure data from Inchon Port is analyzed and the berthing rule based on formal materials and experiences is constructed. A Port-Simulation program to analyze the effects of the changes in ship arrivals, service capacities upon the demurrage is constructed and several scenarios are analyzed. It is expected that we can use the simulation results in order to prepare proper service levels and plan appropriate investment strategies.