The sheep half-hard cheeses were produced by rennet coagulation: a. with the thermopfilic starter addition and b. with mesophilic stater addition. The changes of different nitrogen substances forms in cheeses during 42 days ripening storage period were examined. The significant influence of starter kind and of ripening time on changes of soluble nitrogen substances content, ammonium nitrogen substances content, amino acids nitrogen substances content and non-protein nitrogen substances content was established in tested cheeses. The cheeses produced with mesophilic starter addition had the significantly higher non-protein nitrogen substances content, ammonium nitrogen substances content and amino acids nitrogen content, when soluble nitrogen content was lower than in cheeses produced with thermophilic starter addition.