University forest parks can play a major role in conserving wood biodiversity. However, this woody biodiversity is still poorly understood. The objective of this study is to study plant biodiversity of the Faculty of Agronomy of the Abdou Moumouni University of Niamey (UAM) through the quantification of wealth, the specific composition and description of the population demographic structure of the settlement. The forest inventory was carried out on ten (10) 2500 m2 squares following a radiary transect. Diversity indices (Shannon, Piedlou and specific wealth), systematic composition (number of genders and families) were used for woody floristic analysis. The density, the distribution of woody according to the classes of diameter and height, the potential for regeneration were analyzed to assess the structure. Plenty-dominance character to appreciate the phytosociology of the stand. The study identified 1110 individuals representing 36 species belonging to 27 genee with 18 families. The Fabaceae (25%) is the most dominant family ( Tamarindus indica L. , Parkia biglobosa (Jacq) R. Br. ex G. Don. , Acacia Senegal (L) Willd , Bauhinia rufescence Lam , Faidherbia albida (Del.) A. Chev., Prosopis juliflora (Sw.) DC) in spaces of the Faculty of Agronomy of the University of Niamey with a dominance of Prosopis juliflora (Sw.) DCat more than 50%. The average density of woody plants is 444 ind/ha. Dominated by Calotropis procera (Ait.) Ait.f., (54 ind/ha) and Prosopis juliflora (Sw.) DC (224 ind/ha). Native species dominate the flora of the site. The structure is marked by the dominance of shrubs marked by Calotropis procera (Ait.) Ait.f., and Prosopis juliflora (Sw.) DCreflecting a rejuvenation of the woody stand. However, anthropogenic pressures and the absence of a policy for managing the faculty's spaces may be at the root of the reduction of this floristic diversity in the medium to long term. This is why actions (closure, monitoring) must be taken to safeguard this plant biodiversity.