Abstract: The reference power values of a ship’s power source are defined based on the actual load-power curve at typical working conditions by means of mean value method and low pass filtering method. The objective function for optimizing total cost and total weight of the system is constructed with life cycle cost of the cell integrated. The model and number of storage elements are defined as the decision-variables. The optimal capacity configuration of hybrid storage system is calculated by means of the second-generation non-dominated sorting genetic algorithm under the constraints in peak power requirement and maximum energy requirement.