The research presented in this paper is aimed at improving the comprehensive hydrodynamic performance of a ship during ship optimization design. To reach the improved hull form, four stages should be done, which includes hull form modification, hydrodynamic performance evaluation, surrogate model building and optimization process. There are several design variables related to hull form modification. This paper deals with free-form deformation (FFD) for modifying the initial hull form, an OpenFOAM-based CFD solver, naoe-FOAM-SJTU, for calculating ship resistance and motions and an improved non-dominated sorting genetic algorithm (NSGA-II) as optimization method. The DTMB 5512 hull is selected as an initial hull form and carried to be optimized with the minimum resistance and vertical motion in regular head waves through the stages and methods as is mentioned above. Finally, optimized hull forms are obtained. The results of optimization procedure demonstrate that the optimized hull forms yield the improvement in both resistance and seakeeping performance.