In this paper, we clarify the diversity of public space in a local city based on a questionnaire survey in the Otogawa Riverfront District, Okazaki City, Aichi Prefecture, using biodiversity. As a result, it can be said that there is α-diversity in public space depending on user att ributes and activities, and β-diversity in public space and in the same spatial category. Based on the above, α-diversity and β-diversity occur in public space in the Otogawa Riverfront District, Okazaki City, Aichi Prefecture, and there is a diversity of public space.