Probiotic lactic acid bacteria are widely involved in the production of fermented dairy products due to their particular metabolic activities and potential beneficial effects. The production of lactic acid is essential for the production of fermented dairy products and gives them a typical flavour. Acidification, the production of organic acids and other antimicrobial compounds, plays a major role in the preservation of dairy products and contributes to the inhibition of germ contamination.The present work was reserved for the study of the effect of probiotic lactic strains(Lactobacillus plantarum and Lactobacillus fermentum), isolated from raw bovine and camel milk, on the quality of an uncooked pressed cheese of the type "Saint-Paulin" made from Tunisian sheep's milk. A study of the evolution of the main physico-chemical, microbiological, biochemical and sensory characteristics of the four cheese samples during ripening and storage at + 4 °C was carried out.