The computational chemistry has been mainly used as the support to the experiment especially the visualization of severe conditions are needed. These dangerous or difficult experimental conditions might be reproduced using computer graphics method. Especially, computer chemistry becomes the observation tool for the dynamic behavior of the atoms or molecules. In this paper, we will review our studies on the behavior of molecules in the zeolite nano-pores, the organic molecules in the metal interfaces etc. Recent studies in our laboratory will be also introduced.