Abstract: The bitterness is a property of flavor created in connection with the accumulation of bitter peptides in cheeses arisen through various effects during ripening. In this study, bitter peptides are isolated from Turkish White Cheese (TWC) and Kasar Cheese by using UF, gel filtration, RP-HPLC techniques. The most bitter fractions in cheese samples were in a molecular weight range between 500 and 4000 Da for TWC, 200 and 700 Da for Kasar cheese. Sensory evaluation on the HPLC eluants revealed that bitterness found in various position but the most bitterness intensity was detected at the hydrophobic region of the chromatograms for TWC and it has been found that the bitter fractions of Kasar cheese contains high level of phenylalanine and tryptophan.