Recently, in the field of scientific calculation, the tendency to introduce parallel computer becomes increase. Therefore, converting methods from conventional sequential programs to correspondent parallel ones are required. However, vast amounts of skill and knowledge for the parallel programming are needed to programmer. In this study, we propose introducing the 3D visualization system called NaraView as those programming environment. Naraview analyze the data dependence in the programming code, and visualize their relations. Since the parallelizable code have typical features, NaraView would reveal them visually. We showed the effective parallelizing method, which have those typical features in the loop structure with concrete program code.