Blood was taken from four health volunteer donors into plastic bags containing Citrate-Phosphate-Dextrose (CPD) and Acid-Citrate-Dextrose (ACD) anticoagulant and stored in blood bank refrigerator. Blood pH, HCO3, ammonia, plasma K, and Na were measured on 0,1,2,3,6,10,14,16 and 21 day of storage. Blood pH and HCO3 decreased an plasma K and blood ammonia increased in both ACD and CPD blood with storage. Blood pH, ammonia and plasma K levels became significantly higher in CPD blood than in ACD but HCO3 and Na did not show any significant changes.