This experiment was carried out to study the ripening of control cheese made with lactic acid bacteria only and yeast cheese made with lactic acid bacteria and yeast (C. lipolitica, C. pseudotropicalis, S. fragilis, D. hansenii 4193), with 0, 2, and 5% levels of salt content by the modified kosikowski`s method (1977). The work reported here determined the degree of proteolysis in the cheese for 12 weeks of ripening under 5, 10℃ ripening temperature. The results obtained are summarized as followed: 1. WSN and soluble tyrosine contents in cheese were increased with ripening period. WSN contents of yeast cheese were higher significantly (p$lt;0.05) than those of control cheese at 12 weeks of ripening. Also WSN and soluble tyrosine contents of unsalted cheeses and the cheeses ripened at 10℃ generally had higher than those of other cheeses. Average WSN contents of control cheese (No. 1) and yeast cheese (No. 2,3,4,S, 6) increased from 0.31, 0.33, 0.58, 0.30, 0.34, and 0.30%, respectively after manufacture to 1.24, 1.45, 1.53, 1.49, 1.61, and 1.45%, respectively at 12 weeks of ripening. The ripening period, salt contents and ripening temperature had significant effects (p$lt;0.01) on the WSN and soluble tyrosine contents.