Vietnamese society during the French colonial period (1867 - 1945) was marked by the French colonization of three provinces in the western region of Cochinchina, turning this land in particular and Cochinchina in general into a colony of France. At that time, Southwest Vietnam still had many deserted areas, interlaced rivers and canals, which were not convenient for exploitation. However, the Southwest region will bring great benefits in terms of rice, seafood, etc. if it is invested. Therefore, the French colonialists boldly invested in irrigation and drainage in the Southwest region in various forms such as: dredging the old canals, digging a number of great canals, etc. to serve economic, political and military purposes for France. Therefore, the irrigation and canal system in the Southwest region had many changes during this period. Residents’ mobility became easier, the trade between regions becomes favorable, that has contributed to the economic and social transformation of the Southwest region. However, within the scope of this article, we mainly refer to the digging and dredging of canals in the southwestern region of the French colonial period; thereby drawing some comments on the characteristics of the canal system in the Southwest of Vietnam during this period.