The use of the resources of the Anjouan rainforests is a traditional activity known by families to meet their daily needs. The objective of this study is to qualitatively and quantitatively evaluate the most used plants for sustainable management with a view to their preservation.The diagnostic work covered several variables. Floristic inventories in nine (9) sites were carried out using the Duvigneau transect and Braun-Blanquet plot methods. Surveys were carried out in seven (7) villages and the most used species were evaluated according to the calculation of the Lance index. About 280 species distributed in 24 families and 200 genera with 25 endemic species have been identified. Ocotea comoriensis, Weinmannia comoriensis, Tambourissa leptophylla, Khaya comoriensis and Brachylaena ramiflora were cited as the most used. The heavy use of wood for energy, timber, care and fodder is proving to be the main cause of their vulnerability. Their availability in the field is low and they are in difficulty of regeneration. The biological characters, taxonomic knowledge and habitats of the most used species are known. The uses in traditional medicine of certain species have given rise to avenues for research on active substances.