This research spatially precisely re-presents the locations of economic activities of Tainan City in 1934 by applying geographic information systems (GIS). Base on the empirical data mentioned above, the subsistence productions of a modernized colonial city are physically visualized as a map of industries and intellectually recognized as the nature of the socioeconomic dimension of settlement. First, by spatial analysis, the heatmap of economic activities is visualized and showing that the traditional socioeconomic-spatial structure had not yet been replaced by the modern urban plans. However, some changes are obviously observable when the distributions and concentrations of several important industries are analyzed. Second, the facts of co-existence of various traditional and modern subsistence productions of three planned streets are narrated. In 1933, a Japanese merchant opened a mall on the cross of Suehiro-cho Street and Seimon-cho Street where the former was a new axis of the city in the urban plan. Meanwhile, a Taiwanese merchant built a street-house-cum-shop on the cross of Hon-machi Street and Seimon-cho Sreet where the former was the traditional main street of Tainan City in Qing Dynasty. Secondly, Nonetheless, finally, in the traditional allies, the nature of settlement about livelihood-earning is recognized. The subsistence productions in the streets and allies are narrated as how ordinary people reacted to the macro transformations, interpreted as the reality about how people survived within settlements and the societal continuity.