This paper explores the driving forces to the decline of Liugong Canal built in 1740s, which once served as the artery for transporting irrigation water and the dominate landscape feature in Taipei Basin. During the post-war urbanization, Liugong Canal disappeared with limited documentation by the authority concerned, leading to the difficulty for renovation project nowadays. Thanks to Taiwan Academia Sinica's recent digitalization of historical archives, new possibilities came about to trace the landscape shift of Liugong Canal. By integrating historical maps from 1920s~1980s, it is clear to see the geographical change of canal declining from the lower (northern) to the upper (southern) part in accordance with the road and urban sprawl of Taipei. The area Da-An Aistrict, where Liugong Canal ran through several university campuses and historical residential areas, were further examined to specify the events undermining the waterway system at local scale. The result shows that the transition of historical waterway not only lies in external factors such as road and building development, but also internal factors in relation to the size and converted function of the original canal.