Experimentally produced kashar cheese were deeped into the solutions which contain varies rates of potassium sorbate (0, 1%, 2%, 3%) and the effects of potassium sorbate on the chemical and microbiological properties of the cheese were investigated at the 1 st, 15th, 30th and 60th days of the ripenng period. Potassium sorbate did not show any effects on the chemical properties; the moisture, fat. sah and ash contents. However, it decresed the percent of acditiy values and increased the pH values of the samples. On the account of microbiologically effects of potassium sorbate, it effected on the account of Staphylococcus-Micrococcus microorganisms and mould and yeast.