Starch gel electrophoresis method was used to phenotype : casein and milk serum proteins for 110 Turkish Native Black (TNB) cows. Frequencies were: alpha(s1)-casein A 0.000,alpha(s1)-casein B 0.925, alpha(s1)-casein C 0.075;beta-casein A 0.840,beta-casein B 0.118,beta-casein C 0.042;beta-lactoglobulin A 0.234,beta-lactoglobulin B 0.766.beta-casein and beta-lactoglobulin loci were not in genetic equilibrium. However,the herd was in balance for alpha(s1)-casein. The absence of genetic equilibrium for the 2 loci can be explained by chance as the herd was very small. The effect of migration and selection except for natural selection were weak in this herd.