This work was a literature review of the available data on the plant diversity in protected areas in Niger. It was based on several studies carried out in the period from 2005 to 2021 in nine (9) reserves of Niger. It aimed to assess the current state of the floristic diversity and ecosystem services in these protected areas. The results revealed the information on species richness, ecological spectrums and ecosystems services provided to local population living around these protected areas. A total of 648 plants species, mostly herbaceous, and dominated by Poaceae, were recorded. The spectrum of biological types is dominated by Therophytes (43.57%) and Microphanerophytes (19.07%), which are characteristic of Sahelian vegetation. The chorology revealed a predominance of multi-regional African species and species with a wide distribution. The study highlighted six (6) main categories of ecosystem services for local populations: human food, fodder, traditional pharmacopoeia, energy wood, service wood and craft wood. This review showed that the assessment of plant diversity in the protected area of Niger was far from exhaustive, and much remains to be updated.