The changes of blood gases, K and glucose levels of ACD banked blood according to the days of storage were observed. The samples were taken from the blood stored in the blood bank of Dong San Medical Center just before transfusing them in to patients. The results were as follows: 1) The pH value of one day stored blood was 6,720+/-0.0035. The PH gradually decreased according to the number of days it was stored which was significant statistically(p<0.05). 2) The O2 tension of one day stored blood was 24.1+/-3.25 torr and there was no significant changes in O2 tension according to the storage time. 3) The K level of one day stored blood was 5.7+/-0.5mg and this increased gradually as the storage time increased which was statistically significant(p<0.001). 4) The CO2 tension of one day stored blood was 133.1+/-6.4 torr and this increased according to the days of storage but it was not significant statistically. 5) The blood glucose level of one day stored blood was 338.5+/-0.5mg% and there was no significant increase or decrease as the storage time increased.