A linker-contained R-phycoerythrin (R-PE) complex was obtained by the Sephadex G-150 column chromatography from the Polysiphonia urceolata phycobilisome (PBS) that was disassociated at 37 °C for 6 h in the dilute phosphate buffer (pH 7.0) with 5% (m/v) sodium dodecyl sulfate (SDS). The R-PE complex showed three absorption peaks at 498, 538 and 567 nm, and a fluorescence emission maximum at 578 nm. Polypeptide analysis of the complex by the 8–25% (m/v) gradient SDS–polyacrylamide gel electrophoresis demonstrated that it contained three red subunits, αPE17.6,βPE19.2andγPE31.0, and a colorless 35.3 kDa rod-linker LR35.3. Polypeptide proportion of the complex demonstrated that it was a hexamer in aggregate form γPE31.6αPE17.6βPE19.23LR35.3αPE17.6βPE19.23γPE31.6 which is proposed to originate from a rod assembly of hexamer–linker–hexamer the substructure αPE17.6βPE19.23 of which was decomposed off from the ends of the assembly during the PBS dissociation. The distinctive stability of the prepared hexamer is attributed to a large extent to the electrostatic interaction among its polypeptides, but not to the hydrophobic interaction.