Fluorescence intensities of water-soluble β-(1,3-1,6)-D-glucan (β-1,3-glucan)-complexed porphyrin derivatives were very weak as a result of self-quenching. However, β-1,3-glucan-complexed tetra(aminophenyl)porphyrin exhibited ‘off-state’ to ‘on-state’ fluorescence switching activity by intracellular uptake. Furthermore, the internalised complex showed a high level of photodynamic activity toward HeLa cells under photoirradiation at long wavelengths.