Granulogenesis in netrophil and eosinophil leucocytes of standard (+/+), monorecessive silver-blue (p/p) and direcessive sapphire (a/ap/p) adult mink were studied. The leucocyte abnormality like Chediak-Higashi syndrome (CHS) was demonstrated in sapphire mink. Defect of granules is formed in leucocytes of bone marrow at mitotic and post mitotic stages of maturations. The largest degree of disturbance (maximal size and minimal number of granules) was reveal in bone marrow and blood mature leucocytes. Minks with aleutian mutation (a/a), including sapphire mink can be used as model for research biology and pathology of cell organelles.