The Manga located, in the South-East of Niger knows wind erosion. This form of degradation favored the creation of sharp dunes. To remedy this situation, programs to fight against sand dunes are implemented. This study is conducted in Guidan Kadji (Maïné-Soroa). It compares the herbaceous flora of a treated dune that has received manure, a natural course and a living dune in the vicinity of Guidan Kadji. The method of aligned quadrat points was used for the phytosociological study. The treated dune has 24 species, 10 species for the natural course and 3 species for the living dune, the best represented families are the Poaceae with 9 species. Therophytes occupy more than 80% of the gross and weighted spectra. The species. Guineo-Congolese-Sudanese-Zambézian is the dominant phytogeographic type with more than 70% in the gross and weighted spectra. The cover is 4.25%, 71.02% and 95.81% for live dune, treated dune and rangeland respectively. The qualified forage is 1339.65 kg DM/ha or 1.33 T DM/ha for the natural dune versus 703.44 kg DM/ha or 0.70 T DM/ha for the treated dune. It is practically null (2.04 kg DM/ha or 0.002 T DM/ha) on the live dune. Overall, the regularity (>0.60 bits) is high and the Sörensen similarity (>80%) between the treated dune and the natural course is high. This study demonstrated that dune fixation can restore the flora of degraded dune systems, especially if the site is close to residential areas.