In order to study the combination of bilirubin with globin and also the combination of bilirubin with globin+albumin, the author estimated the absorption curves by means of paper electrophoresis using veronal buffer solution at pH 8.5 as the electrolyte and by paper chromatography at the first dimension using a 2% cane sugar solution as a developer, as well as by D-K type Beckman's autospectrophotometer; and obtained the follo wing results. 1. Sodium bilirubinate that is a direct bilirubin and dibasic acid bilirubin, an indirect bilirubin, both haye the capacity to combine with with globin. 2. Such combinations of bilirubins and globin do not control the mode of bilirubin to the diazo reaction. 3. When sodium bilirubinate is dissolved in the mixed solution of globin and albumin, it will combine with either one, namely, with globin and with albumin. Moreover, in this instance the mode of the proteins just as in the mode of sodium bilirubinate, shows a direct response to the diazo reaction but never an indirec response.