Abstract
The aim of research is to clarify the origin of graceful shape of Hakusui dam. Authors thought that it was necessary to grasp the idea over a design and construction of a designer. Therefore, Attention is paid to Yasuo Ono, who was a designer and a construction supervisor. 123 construction photographs that he took are arranged, depending on construction stages, photographing places, and targets for photograph. Combining their patterns, the analysis is carried out. A reason why Yasuo Ono took photographs is guessed. Thus, the parts of Hakusui dam, which he thought to be important, are identified.