This studyanalyzed the single nucleotide polymorphism (SNP) of 118 Turkish Awassisheep. Itwas aimed toestimate the breeding value, additive, dominant variance and allele substitution of prolactin gene and their effect on milk production. Three genotypes were found, AA, AB and BB, using PCR-RFLP technique and HeaIIIrestriction enzyme (intron2). Breeding valuesof these genotypes were -1.9082, 0.8168 and 3.5438 respectively and dominant deviation were -0.2989,0.455 and -1.0309 respectively, the values of genetic variance (VG),additive variance (VA) and dominants variance (VD) were: 8.11943; 3.8113 and 0.30813 respectively, the substitution effect mean of A and B alleles were 2.726 and -2.726. Whereas,the average gene effect of A and B alleles was 1.7719 and -0.9541 respectively. It can be concluded that selection of A allele and its actual value as one or two copies in individuals improve the milk production of Turkish Awassi sheep.