This paper aims to clarify 3D spatial composition of Civic Center in the early Showa era with bird's-eye view pictures by YOSHIDA Hatsusaburo in cases of 18 prefectual capital cities based on Japanese Castle-Towns. First, I indicate necessity of complementing by topographical map, photographs and pictures in case of using bird's-eye view pictures by YOSHIDA Hatsusaburo as research material, because characteristic of them is deformation, and examine their possibility of research material. Findings are as follows: 1) We can grasp arrangement conditions and facades of each government and municipal offices, whole construction of Civic Center and physical state of surrounding Civic Center with bird's-eye view pictures, 2) As a result of analysis 3D spatial composition of Civic Center with bird's-eye view pictures in cases of 18 cities, there was principle of 3D Urban Design answer to spatial composition of Castle Districts such as main road, moat and skirt of mountain.
