An aqueous pseudoisocyanine dye solution in a soda lime glass optical cell exhibited the new absorption band of a J aggregate at around 577 nm (J(L) aggregate) at room temperature. The J(L) band was slightly red-shifted and broader (hwhm : similar to 130 cm(-1)) compared to the previously reported J band (J(S) band; peak, similar to 572 nm; hwhm, similar to 70 cm(-1)). Since formation of the J(L) aggregate was not observed in a quartz glass cell, it was concluded that J(L) aggregate formation was induced by interactions between the dye and the soda lime glass surface. Total-internal-reflection fluorescence spectroscopy proved that the J(L) aggregate was distributed only in the vicinity of the glass surface, whereas the J(S) aggregate was produced in the bulk water phase.