Light-harvesting antennas, for example the LH2 complex in purple bacteria, sophisticatedly align chlorophyll molecules in a cyclic fashion by using protein scaffolds. However, artificial preparation of the circular LH antenna model without any templates has not been reported. We demonstrated the construction of ring-shaped supramolecules by self-assembly of a semisynthetic chlorophyll dimer through a transformation from wavy fiber-like aggregates.