Abstract: With the implementation and promotion of Rules for Green Ships, more and more attention has been paid by the maritime industry to the ship energy efficiency index. In order to evaluate the function relationship between speed and effective horsepower, and acquire the accurate flow field information of twin-skeg ships, a method for resistance prediction of twin-skeg ships based on the Computational Fluid Dynamics (CFD) theory is outlined. Numerical simulation and resistance prediction by FINE/MARINE for a twin-skeg passenger ship advancing at different speeds are carried out respectively. The effects of the mesh characteristics, calculating speed range, and existence of appendages such as rudders on resistance are discussed. Comparisons between present results and corresponding experimental are made, showing that the prediction error can be controlled below 3%. The results demonstrate that the proposed method is efficient enough to be realized and will meet the engineering requirements.