The number of incidents leaking of classified information has increased. To prevent leakage of information, it is important for users to understand the usage of classified information. To understand the usage of classified information, an method has implemented that monitors operations on the classified information and logs those operations. However, because an analysis of logs is necessary for understanding the usage of classified information, it is difficult to prevent leakage of classified information. We proposed the function to trace the classified information diffusion and detect a leakage of classified information. However, to understand the usage of classified information from the function by users, it is necessary to analyze the log in text format. Therefore, it takes long time to investigate the cause of the leakage of information. This paper proposes a function to visualize diffusion path of classified information. The function enables us to visualize the diffusion path of designated files that contain classified information. In addition, the function can visualize the diffusion paths focusing on the designated period of file operations. This paper also describes the implementation of the proposed function by extending the existing tracing function of classified information.