The examinations of 30 blood samples each preserved with three Yugoslav different ACD-solutions were performed. The blood samples were stored at 2-6 degrees C and examinations were performed at the day of blood donation and after on the 7th, 14th and 21st day during the storage. Differences in hematocrit (well known dilution effect of the ACD-solutions used) and intensive morphological and chemical changes were found in all blood samples regardless the type of ACD-solution used. It was shown that the permanently increasing number morphologically altered erythrocytes (echinocytes and spherocytes) and the excessive release of hemoglobin and potassium from erythrocytes were occurred during the storage of blood samles. Too, there were noticed significant decrease of pH values enormous accumulation of ammoniac and other metabolic producta.