Three phycoerythrins ie B-phycoerythrinl (B-PE-1), B-phycoerythrin 2 (B-PE-2) and b-phycoerythrin (b-PE) from Rhodosorus marinus were purified to electrophoresis purity: The molecular weights of the three phycoerythrins and their subunits were determined. The absorption spectra and the fluorescence spectra of the three phycoerythrins were measured. The absence or presence of an absorption peak at 498nm represents the major difference between the b-PE and B-PE. The amino acid compositions from the three phycoerythrins are relatively rich in aliphatic and acidic amino acid. This is the reason why the isoelectric point of the three phycoerythrins tends to acidity.