This study showed spatio-temporal changes about hotel availability during large scale events in Niigata and Tokushima prefectures using big data acquired from the Vacancy Search API of Jalan Web Service. As a result, this study clarified the decrease in the number of vacant rooms in hotels around the event venue 120 days before the event day, its extent of the spatial spread centered at the event venue, its time-series change, and the increase in hotel charges. In addition, at the end of this paper, with regard to vacancies information acquired from this Web API, the applicability of big data as new location information is described.