Study of polyphenols of the leaves of an ibero moroccan endemic, Thymelaea lythroides. Thymelaea lythroides (Thymelaeacees) is an endemic of the region of the Gharb (forest of Mamora). It is part of the panoply of the medicinal and aromatic plants of Morocco. Because of the lack of phytochemical informations on the species, some previous studies had for object a research of the antifungal activity of its extracts and a phytochemical screening. This last permitted to put in evidence the wealth of the plant in different secondary compounds. Thus, the present work intends to study the polyphenols of the leaves of Thymelaea lythroides and specially the flavonics aglycones and the anthocyanidins. The survey demonstrated the existence of different molecules belonging to the class of the flavonols, whose identification revealed the kaempferol and quercetine. In addition to two acidic phenols, identified as the cofeique acid and the genticique acidic and two anthocyanidins, the delphinidine and the cyanidine.