The biological reserve of Sidi Boughaba has a unique plant biodiversity, with many animals, including birds, finding refuge there. Data on this biodiversity is old and incomplete. This phytosociological study was carried out to define the vegetation structure of the area. Stratified sampling was carried out and 124 relevés were recorded. Multivariate statistical analyses (correspondence factorial analysis and hierarchical ascending classification) used to process the relevés revealed the presence of 9 plant groups, including 4 plant associations and 5 subassociations, which belong to 3 phytosociological classes (