Beyaz peynir, Turkish white-brined cheese, was produced with six different strains of Lactococcus and ripened at 6-8 degrees C. Two of these were Lc. lactis subsp. lactis UC317 and NCDO763, while four of them were Lc. lactis subsp. cremoris SK11, HP, Wg2 and AM2. To determine their performance in manufacture of Beyaz cheesemaking, the activity of six different strains of Lactococcus were monitored during cheese production by determining the curd acidity. Also, their proteolytic and lipolytic activities were tested by determining nitrogen fractions and free fatty acid contents, respectively, after 3 days of ripening. These cheeses made with each strain of Lactococcus did not differ significantly in pH decline during cheesemaking. The gross compositions of the fresh cheeses were found to be similar; however, the cheeses made with HP and Wg2 had the lowest and highest levels of salt-in-moisture content, respectively. Water-soluble nitrogen, 12% trichloroacetic acid soluble nitrogen, total free amino acid and total free fatty acid contents were significantly influenced by using different strains of lactococci in manufacture of Beyaz peynir. All strains, except for Wg2 and AM2, gave a satisfactory result in chemical quality of the cheese; however, some differences were observed.