Black Soybean (Glycine soja) has a similar protein content compared to yellow soybean (Glycine max). Yellow soybean has been extensively used in protein concentrate manufacturing, otherwise the utilization of black soybean is still rarely found. The extraction of protein from both soybean have been done by applying the alkaline method using NaOH to dissolve the protein and continued by precipitation by using HCl. The yields for both yellow soybean and black soybean concentrate are 13,4% and 12,8%. The protein content of both yellow soybean concentrate and black soybean concentrate are 77,87 % and 78,77 %. Black soybean concentrate has higher bulk density, degree of whiteness, water absorption, oil absorption, emulsion capacity, emulsion stability compared to yellow soybean. But it has a lower foam capacity and foam stability than yellow soybean. Both concentrate have the highest solubility at pH 12 and lowest solubility at pH 4.