Lygeum spartum L. (Poaceae) is one of the most abundant perennial rhizomatous grasses found in Algerian steppes. In the aim to study its physiological behaviour in salt medium at early stage, experiments were carried out under hydroponic culture added with NaCl, 0, 50 and 100 mM. Two weeks after salt treatment, growth was decreased only by 100 mM NaCl. Osmotic adjustment was associated to high Na+ and Cl- accumulation, however soluble sugars contributed slightly to osmotic adjustment.