Abstract 1. 1. The interaction of albumin with haeme was studied by measuring the absorption spectra in the Soret region. Albumin was confirmed to have one strong binding center besides some weaker ones; from the latters haeme can be removed by ion exchange chromatography on DEAE cellulose thus forming an equimolar haeme-albumin complex, 2. 2. Haeme transfer within the ferrihaemoglobin-albumin system was studied using CD spectra measurements in the Soret region. The transfer mechanism was described by the four consecutive reactions: G 4 X I + A = K I G 4 X I−1 + AX (i = 4.3.2.1). characterized by equilibrium constants K1 = 0.39; K2 = 0.22; K3 = 0.032 and K4 = 0.15. 3. 3. The transfer of haeme in the haeniealbumin-apohaemopexin system was investigated by means of difference absorption spectra in the Soret region. The system can be defined by a simple stechiometrie equation AX + Hx = K A + HxX characterized by the equilibrium constant K = 75.