Mbujimayi, a post-colonial city in the Democratic Republic of Congo, is experiencing urbanization characterized by the absence of forward-looking planning, which has led to land speculation and the anarchic occupation of urban space. This article proposes to analyze the urban dynamics of the 1950 and 1960 urban space (between 1950 and 1960) and the spontaneous space, more than 60 years after its independence (from 1960 to 2020). The unprecedented population growth of Mbujimayi from 21875 inhabitants in 1950 to 3490211 inhabitants in 2020, mainly following the repression of the Shaba (Katanga) to the Kasai of the Baluba – Lubilanji and other ethnic groups in 1992, has caused the total consumption of the base of the Mbujimayi area with an overflow of the area. The latter has reached 145.80 km2 in fact, including 106.86 km2 of legal area. Thus, the extension of the city of Mbujimayi blocked by the natural limits (the rivers Muya in the north, Kanshi in the south and Mbuji-Mayi in the east) was built only in its western part, in the commune of Bipemba. It has created two boundaries, one legal which remains immutable, and the other de facto which is mutable in the Mulenda and Mukumbi sectors of the territory of Lupatapata. The coexistence of these two boundaries legally creates a biased situation in the delimitation of this city.