This study aims to examine the construction process of the Duntu Line, completed in 1933 following the establishment of Manchukuo, and to analyze the architectural characteristics of its railway stations. The Duntu Line represented the core and final section of the Jihui (Jilin–Hoeryeong) Railway, which was part of Japan’s imperial strategy to connect Japan, Manchuria, and Korea after the Russo-Japanese War. The study is organized into three parts. First, regarding the background of the line’s construction, the process of route selection is reviewed through technical reports such as the “Third Route Survey Report” to clarify how the Dunhua–Tumen section was determined. Second, the section on architectural design and construction examines the organizational structure by distinguishing the types of railway architecture, design and construction periods, and the roles of design, supervision, and construction. Finally, the architectural characteristics of railway stations are analyzed using primary sources such as construction records and architectural journals, focusing on station grades, spatial layouts, structural systems, and architectural features. By exploring the background of the Duntu Line’s construction and the architectural formation of its railway stations, this study reveals the significance and influence of the Duntu Line within the broader process of completing Japan’s imperial railway network in Manchuria.