In the early twentieth century, Dong Du Movement was initiated and led by Phan Boi Chau, leading to a new trend in the national liberation movement in Vietnam. Nord-Annam was one of the areas where Duy Tan Association operated; Dong Du Movement in this area also developed strongly, drastically and distinctively. However, previous studies have not yet simulated and analyzed in details of the Dong Du activity in Nord-Annam in the early twentieth century. This article summarizes the unpublished sources of the French Government and reconstructs the movement in Nord-Annam on the following facets: the participant of the movement; funding; the number of young people who studied overseas; the scale of the movement… The article is intended to enrich the local history in the early twentieth century in particular and to study Dong Du Movement in the history of Viet Nam in general.