Visualization has great importance to extract essentials included in simulation data and to derive scientific discovery from the analyzed data. However, only perfurming simulation is not sufficient. Post processing, that is visualization and data analysis, is recognized as the very important basic technology that supports numerical simulation. Recently, K computer achieved the world fastest record in TOP500 and is anticipated its utilization in science and engineering fields. Extremely high parallelism and computation performance will be required for data processing and visualization algorithms since the high-end parallel supercomputer generates large-scale datasets. This paper describes the trend of post processing technology, which becomes more and more important.