This study has been done to investigate differences within breed and between breeds and to determine the average aktive NOR chromosom numbers of Akkaraman (AKK), German Black Mutton (GBM) and crossbreed (F₁). Ten individuals (5 male and 5 female) from each breed were used as material in the study. The chromosome preparations oblained from sheep were painted with NOR-banding method. Thirty metaphase spreads were examined in the chromosome preparation ol each sheep and the average active NOR numbers were determined. The general average active NOR numbers of female and male AKK, GBM and F₁ cross were estimated 6.10, 6.33 and 6.03; and 6.03, 6.69 and 6.63 respectively. The variation between male and female of AKK, GBM and F1 cross were found not significant. The general breed averages active NOR numbers of AKK. GBM and F₁ cross were calculated as 6.06, 6.51 and 6.33 respectively. There were no! significant variation between GBM, AKK and F₁ cross. The study; there were a variation individuals of AKK and GBM and F₁ crossbreed connected with average active NOR numbers. It is concluded that more studies should be done to investigate the relationship between average active NOR chromosom numbers and yields for improvement of animal production in livestock.