Visualization of numerical simulation data is indispensable to intuitively understand natural phenomena. In this study, state-of-the-art visualization techniques to represent ocean general circulation model will be introduced. We have developed a multi-dimensional color map to visualize ocean currents effectively. In order to extract feature emphasis regions, a cluster analysis method, which is one of multivariate analysis, has also been developed. The multi-dimensional color map is optimized using extraction result.