Abstract: Introduction: There are two types of methods for measurements of total hemoglobin concentration (tHb).One is absorbance spectrum method, and the other is electrical conductivity method.Blood gas analysis apparatus ABL77 (Radiometer, Copenhagen) determines tHb concentration by electrical conductivity.In the current study, we investigated the effects of hemolysis and electrolytes on the accuracy of tHb measurement using ABL77.Methods: Blood samples were obtained from 5 volunteers.Some of them were demolished by freezing and thawing for hemolysis.Original blood samples and hemolyzed samples were mixed at the volume rate of 1 : 9 and 5 : 5. Their tHb concentrations were determined by using ABL77.Differently, 25 ll of 10%NaCl solution was added to the 1975 ll of blood samples at the volume rate of 1 : 79. Results and conclusion:The mean concentration of tHb of original blood samples was 15.49 AE 1.24 g/dl.The tHb of hemolyzed blood samples was significantly lower; 12.09 AE 0.93 g/dl (P < 0.05).The tHbs of the mixture of the original samples and hemolyzed samples were 15.02 AE 1.06 g/dl (9 : 1) and 13.81 AE 0.80 g/dL (5 : 5).Dose of hemoglobin must not change by hemolysis.In the case of ABL77, however, intracellular electrolytes flow out by hemolysis, and the conductivity of blood solution may be changed.By addition of 10% NaCl solution, hemoblobin concentration should be diluted by 79/ 80.However, Na + increased to around 200 mmol/L, and tHb significantly decreased to 13.05 AE 1.04 g/dl (P < 0.05).In conclusion, we should take account of the condition of blood samples to measure tHb using electrical conductivity method.