Plant extracts have promising results due to their functional and therapeutic properties. This work aims to study the effect of Thyme extract (TE) as an antioxidant, antimicrobial on properties and quality of white soft cheese (WSC). Results indicated that the antioxidant activity (DPPH) of thyme extract was (17.05±0.15) mg TE/g, total phenols value was (25.18±0.05) mg GAE/g and total flavonoids value was (17.29±0.47) mg CE/g. And after studying the effect of different concentrations of thyme extract (10, 20, 50 mg/ml) as an antimicrobial, the results indicated that concentration (50 mg/ml) was most effective for all examined pathogens bacteria compared with other concentrations with significant differences (P ≤ 0.05). Bacillus cereus and Pseudomonas aeruginosa were more effective. than E. coli and S. typhimurium in examined pathogenic bacteria for all concentrations. The highest effect of thyme extract on examined fungi strains was for Penicillium verrucosum. The highest content of phenolic content was for caffeic acid (1868.19 μg/g) followed by protocatechuic acid (1096.49 μg/g). The Chemical properties of white soft cheese were determined and results showed that TS and protein decreased with increasing concentration of TE with significant differences (P ≤ 0.05) and it increase in all treatments during cold storage (30 days). Fat increased with increasing of TE and during storage period. DPPH of WSC which increased with significant differences (P ≤ 0.05) with the addition of thyme extract. Aerobic mesophilic bacteria and psychrophilic bacteria count decreased significantly with increasing TE ratio. The sensory evaluation was acceptable to the arbitrators throughout the storage period; the flavor of cheese supplemented with thyme also received the highest score during the storage period.