The present study was carried out to determine the vital compound in the alcoholic Moringa peregrina leaves extract (MPLEE) and estimate the effect of that extract on the oxidative stability, chemical composition, microbiological and sensory properties of UF-soft cheese made with MPLEE at different concentrations (10, 20 and 50 mg/ml) compared to control cheese and cheese contained 0.02% of butylated hydroxy anisole (BHA). The results showed that the yield of extract was 35% of dry weight of Moringa peregrina leaves, Total phenolics (116.6 mg chlorogenic acid equivalents (CAE)/g extract) and total flavonoids (45.2 quercetin equivalents (QE)/g extract). The main components for Moringa peregrina were rutin, narengin, rosmarinic and hisperdin (17412, 1328, 1047and 984.90 mg/L, respectively). The concentration of the sample that scavenges 50% of the DPPH radicals (SC₅₀) of MPLEE was recorded 500 µg mL^-1. Resultant cheeses were stored in brine solution 6% at 5±2°C up to 90 days. Results showed that, addition of MPLEE had increasing significant effect (P≤0.05) on fat/DM%, total protein/DM%, soluble nitrogen (SN/TN%), non-protein nitrogen (NPN/TN%), salt in moisture% and total volatile fatty acids (TVFAs). On the other hand, titratable acidity was decreased with addition of the ethanolic extract compared to control. Cheese containing MPLEE showed the highest oxidative stability. Also, the extract reduced the total bacterial count in the treated cheese than the control. However, yeast and mould counts showed opposite trend and they were not detected in all treated samples up to 60 days of storage. Also, results showed that, cheese samples containing MPLEE (10, 20 and 50 mg/ml) showed better organoleptic characteristics than other treatments. It could be recommended to use this extract at level of 20 mg/ml as a useful additive to improve the microbiological quality and shelf life of the product