NOVELTY - Preparing heme iron by adding ascorbic acid and sodium citrate to duck blood, centrifuging, lysing the precipitate by alternatively keeping at high and low temperature, homogenizing to obtain hemoglobin, reacting the hemoglobin with alkaline protease and then Flavourzyme (RTM: Protease from Aspergillus oryzae), heating and centrifuging the obtained plasma protein extract to obtain hemepeptide as supernatant and hemoglobin as precipitate, and washing the precipitate with acetic acid, ethanol, and finally water, and spray drying heme iron solution.    USE - The method is useful for preparing heme iron from duck blood (claimed).    ADVANTAGE - The method is environmentally-friendly, since the production process releases no pollutants, and increases additional value of heme iron, and completely and comprehensively utilizes duck blood resource, which is a byproduct of duck processing. The heme iron has protein content of not less than 80%, heme content of not less than 15% and iron content of 2-2.5%.    DETAILED DESCRIPTION - Method for preparing heme iron involves (a) adding 2 g/l ascorbic acid as antioxidant with respect to 0.05-0.1% duck blood, and 4 g/l sodium citrate as anticoagulant with respect to 16.7% duck blood, (b) centrifuging the mixture at 4000 rotations per minute (rpm), and obtaining plasma as supernatant and blood cells as precipitate, (c) lysing the precipitate by alternatively maintaining at cold and hot temperature of -20 degrees C and 90 degrees C respectively, and homogenizing the lysed cell at 120 MPa using dynamic super high pressure microjet homogenizer to obtain hemoglobin, (d) reacting 0.5% alkaline protease with obtained hemoglobin at pH 8.5 and 55 degrees C for 2.5 hours, and then reacting 0.3% neutral protease, and 0.2% Flavourzyme (RTM: Protease from Aspergillus oryzae) with enzyme treated hemoglobin at pH 7 and 50 degrees C for 4.8 hours, (e) heating the obtained hemoglobin at 85 degrees C for 30 minutes, and inactivating enzymes to obtain crude extract of thick plasma protein, adjusting the pH of the extract to 4.5, allowing to stand for 2 hours, and centrifuging the extract at 4000 rotations per minute to obtain hemepeptide as supernatant, and hemoglobin as precipitate, (h) washing the precipitate with 10% acetic acid and 30% ethanol, and washing finally with water, and (i) adjusting the heme iron concentration to 25-30% in the solution, and drying the heme iron by spray dryer to obtain heme iron powder, where the inlet and outlet temperatures are maintained at 195-200 degrees C and 90-95 degrees C respectively.