Code clones (duplicated source code in a software system) are one of the major factors in decreasing maintainability. Many code clone detection methods have been proposed to find code clones automatically from large-scale software. However, it is still hard to find harmful code clones to improve maintainability because there are many code clones that should remain. Thus, to help find harmful code clones, we propose a code clone visualization method and a metrics application on the visualized information. Our method enables the location of harmful code clones diffused in a software system. We apply our method to three open source software programs and visualize their code clone information.