Some research work on energy savings for a sailassisted 76,000 DWT Bulk Carrier operating on the route of Hong Kong-Yokohama was carried out in this paper based on the Northwest Pacific Ocean wind statistics.Firstly, mathematical model of maneuvering motion for a sail-assisted ship was developed.Numerical simulations for the ship with and without sail system were carried out under different wind conditions then.Finally, evaluation of energy savings achieved by the use of sail system for the ship was studied.The result shows that average energy savings on this route for the operating period of one whole year is about 2.8%.