An aqueous extract of thyme was added to the Kareish cheese made of skimmed buffaloʼs milk at 0.5, 2.0 and 3.0 %. Cheese was chemically and microbiologically analyzed during storage. The obtained results indicated that the titratable acidity, ash and total solid and soluble nitrogen increased by increasing the added theme extract, and by the prolonging of the storage. Addition of different concentration of thyme, On the other hand, didn’t affect significantly the total nitrogen, total protein and Protein/DM. The amino nitrogen content significantly increased by increasing the added thyme and with the increasing the storage period. Fat and Fat/DM and Salt and Salt/DM of cheese contents significantly increased by proceeding the storage period. Cheese made with supplementing of with 1% thyme gained the highest total scores (99.4 ), while the lowest of 81.83 was attained for the control. after 15 days. Concerning the microbiological quality, the results indicated thahe Increasing the concentration of added thyme extract resulted in significant decrease in the overall bacterial count. while the increase in cheese storage period resulted in lower increase in the microbiological load, but the increase was lower than the control.