Tomoya MASUDA (1914-1981) was the former professor of department of architecture, Kyoto University, an architect and an architectural theory researcher. But the relations between his works and his thoughts have been studied little up to now. Then, the author studied that relations to evaluate his work through revealing the characteristics of the master plan of EXPO'70 designed by Masuda (Banpaku-keikaku). In the plan of Banpaku-keikaku, Masuda emphasized discernment and manipulation of the topography of the site, the word “topography” was also highlighted in his doctoral thesis (1955); Therefore, the concept of topography on Banpaku-keikaku is the focus in this paper. More specifically, this paper analyzed and compared with each of three master plans designed by Uzo Nishiyama, Kenzo Tange and Masuda in respect of design concept, site planning, and understanding and manipulation of the topography.

 In Nov. 1965, Kyoto University started preliminary study for EXPO’70. And then in Dec. 1965 Nishiyama and Tange were appointed to oversee drafting the original plan. Nishiyama designed the first and the second draft of the master plan, and then Tange designed the third and the fourth draft of the master plan. Masuda's plan was designed as a part of preliminary study before the first draft by Nishiyama. This fact was founded in a unpublished blueprint book 『JEXPO'70会場計画』, that mainly includes the Masuda's plan designed in 10th Mar. 1966.

 he author analyzed Nishiyama's plan in the chapter 3, Tange's plan in the chapter 4, and Masuda's plan in the chapter 5. As a result of analysis and comparison, we found these characteristics of Masuda's plan.

 In respect of design concept, we found that the main purpose of Masuda's plan was showing the theme of the EXPO'70, and to realize the idea that named Keikan-ka(making a new landscape that has a new meaning) and Kankyo-ka(making all of the components of the site to balance and be harmonized.). That concept was totally different from Nishiyama and Tange's concepts that mainly focused on realization of the theme and fulfill the requirements.

 In respect of site planning, we found that Masuda's plan has the largest artificial lake, pavilions are disposed in certain area according to its character, the placement of Theme Zone (named Symbol Area in Nishiyama' and Tange's plan) is different from Nishiyama's and Tange's plan, and the theme of the EXPO'70 is not realized as facilities or buildings of the site.

 In respect of understanding and manipulation of the topography, we found that Masuda explained the site as a part of bigger geographical division than the site, necessity of three-dimensional site planning. Additionally, Masuda didn't place an artificial land in the center of the site while Nishiyama and Tange did. And an artificial lake does not have practical functions but is intended to make a panorama of the site and related to order of pavilions.

 Conclusion is that, in Masuda's plan, Keikan-ka is realized to make the site seen as one united area that means exposition itself or the whole of its site. And Kankyo-ka is realized to make a connection of arrangement between pavilions and the artificial lake; Moreover, these two ideas are mainly realized by discernment and manipulation of the topography includes an artificial lake. In other words, the artificial lake is the pivot of the Masuda's plan, namely they emphasized discernment and manipulation of the topography.