This paper aims to clarify the relationship between the situation of the local society and the expected role of the regional history events which were related to Tokugawa Ieyasu, held in Okazaki city, Aichi Prefecture, every 50 years. From the literature survey, we categorized the events as "traditional type", "participatory type", "viewing type", "outgoing type / installation", and examined the influence on the city from the situation grasp of Okazaki City before and after the regional history events. With each passing times, the "participatory type" events involving contents or places in the Tokugawa clan declined. The 300-year festival and the 350-year festival held when the society changed, such as municipal mergers, showed a new administration and a well-established foundation, the Tokugawa clan was taken up as a symbol of integrating humanity, but in the society The 400th anniversary project held at the time when no change was seen has become more like the national policy such as interregional exchanges and wide area cooperation than the town situation. It is difficult to say that the entire city area is related to the Tokugawa clan by merging municipalities, and even if the city area expands, the spread of the event hosting area may be restricted.
