mLake Biwa is one of the earliest cases of large regional tourism development and scenic preservation in modern times in Japan. This paper clarified the process of developing ideas of scenic tourism and revealed the way of managing the scenic preservation system in Lake Biwa in the Taisho period. In 1914, Shiga prefecture carried out a "Scenic Investigation" with an expectation of hosting foreign travelers and national park designation. Seiroku Honda and Takanori Hongo lead the scenic investigation and evaluated scenic spots as resources for tourism over the whole Shiga Prefecture. And they illustrated ways of developing the scenic areas and building infrastructure and transportation system for tourism. Their plans took the lead in enhancing scenic spots in Lake Biwa. Furthermore, this paper revealed the details of scenic area designation in 1921 and the controversy surrounding the factory construction and scenic preservation. A part of the scenic preservation area was terminated with the aim of industrialization in 1927, then in 1937 the waterfront area was designated as scenic districts under the City Planning Act.