In this study, it was aimed to compare the electrical conductivity (EC) of milk and the California Mastitis Test (CMT) to reveal its importance. In this study, 51 Holstein dairy cows and 204 udder lobes in a commercial herd were used. EC was measured with Milk Checker by applying the CMT results were recorded in the same udder lobe. As a result; as the material used in the present study cows +1 degree CMT has given positive results and that EC of milk in the mammary glands of animals belonging to the 5.81±0.06 mS/cm was detected. In addition, the CMT results with the results of the EC milk were found to be incompatible.