This research focused on the regional and temporal attributes of tuff architecture in Mokpo, spanning the Japanese colonial period and the post-liberation era. It aimed to uncover the distinct regional and temporal features of tuff architecture by integrating concepts from vernacular architecture and regionalism, framed through a lens of critical regionalism. The study traced the historical progression of tuff architecture in Mokpo within this context. A significant part of the research was an in-depth analysis of four constructions by Son Yang-dong, a renowned technician in post-liberation Mokpo, to closely examine the contemporary relevance and regional significance of his work. Tuff, as an indigenous material, distinctly articulates the local architectural character. In line with regional properties of tuff, the material has adeptly responded to contemporary construction needs. This has laid a foundation for the development of innovative building designs and techniques. Tuff architecture is particularly noted for its exhibition of raw material textures, offering a unique aesthetic that diverges from classical Western architectural styles. Importantly, through the examination of Son Yang-dong's contributions, the study highlights the role of Korean builders in an industry dominated by Japanese influences during the colonial period, underscoring a strong regional identity. As a representation of Mokpo, tuff architecture not only upholds and protects regional identity within the broader scope of Western modernization and Japanese impacts but also plays a role in its progressive enhancement.