Nopal a (prickly pear tree) is a kind of plant xerophytes belonging to the family of Cactaceae, the fruit is consumed exclusively in a fresh state. It is claimed to be an excellent source of natural oligoelements which may improve human health and nutrition, it also used in traditional medicine. The objective of this work is to extract and analyze the lipid fraction of prickly pear seeds (Opuntia ficus–indica L.) and to determine the psychotropic activity of prickly pear seed extracts (Opuntia ficus-indica) to achieve a primary pharmacological screening contained in these extracts (aqueous, hydro-ethanol). The oil of seeds is rich in fatty-acids poly-unsaturated, Main fatty acids identified were linoleic (C18:2), oleic (C18:1), palmitic (C16:0), and palmitoleic (C16:1) acids with respective contents 81.25%, 3.70% and 15.03%. These results are returned account that the food quality of prickly pear seeds is very important and its natural source of edible oil containing of the essential fatty-acids. The study of the pharmacological activity showed that the extracts à bases seeds with the tested amounts are endowed with sedative effects, myorelaxant and tranquillizing.