OZET: Sut protein sistemi uzerine yap.lan cal..malar yar.m as.r. a.an sureden bu yana devam etmekte olup genetik, molekuler biyoloji ve biyokimya gibi ileri bilim dallar.n.n katk.s.yla elektroforetik ve kromatografik teknikler gibi yeni analitik metodlar.n geli.imi, sut protein polimorfizmi konusuna buyuk katk.lar sa.lamaktad.r. Sut s...r populasyonlar.nda en yayg.n cal...lan genetik varyantlar ƒ¿s1-Cn, ƒÀ-Cn, ƒÈ-Cn ve ƒÀ-Lg�fd.r. Dunyada ce.itli s...r .rklar.ndaki ƒ¿s1-Cn, ƒÀ-Cn, ƒÈ-Cn ve ƒÀ-Lg lokuslar.na ili.kin gen frekanslar. da..l.m. tablolar halinde verilmi.tir.Anahtar Kelimeler: Sut proteinleri, polimorfizm, s...r.Importance and Meaning of Milk Protein Polymorphism In Cattle ABSTRACT : Studies on the milk protein system have been in progress for more than half century, and contributed to milk protein polymorphism the the improving of new analytical methods like electrophoretic and choromatographic tecniques, together with the contributions of sciences in progress like genetics, molecular biology and biochemistry. Usually, genetic variants studied on milk protein polymorphism in dairy cattle population; ƒ¿s1-Cn, ƒÀ-Cn, ƒÈ-Cn and ƒÀ-Lg. Gene frequencis distributions of ƒ¿s1-Cn, ƒÀ-Cn, ƒÈ-Cn and ƒÀ-Lg loci in various cattle breeds in world are presented to be Tables.Keywords: Milk proteins, polymorphism, cattle .