To analyze the actual state of the linguistic boundary in North Morocco and to situate the linguistic map of Arabic and Berber, the authors were helped mainly by the work of colonial historians. At the end of the 20th century many Moroccan and foreign researchers tried to do this work again without noteworthy changes in the perception of a linguistic map for this region from whence the necessity of another look for these two authors, the evolution is noteworthy because the Berber Language has lost a lot of ground on behalf of Arabic in the North and the South East of Oujda. In the region of Taza, the situation doesn’t seen to change in the some way, because the limits between Arabic and Berber are not as rigid as other idioms, there is even a linguistic union between the two languages.The maps in the appendix to this article illustrate well the fact that the boundary between the two language is not abrupt.