In this paper, the scale effect of flow field around ship is studied by the CFD simulation at model scale and full scale Reynolds numbers in towing condition. A finite-volume upwind scheme, pseud-compressibility and two turbulence models are used as the numerical method. Turbulence models are Baldwin-Lomax turbulence model and SR222 modified Baldwin-Lomax turbulence model, which are included in the category of zero equation turbulence model. Present calculation is applied to Series 60 Cb=0.6 and Ryukou-maru hull form. In conclusion, the numerical calculation can be useful tools in studying scale effect of wake distribution and resistance performance.