We have investigated the optical properties of a synthesized polymer containing perylene tetracarboxylic diimide (PDI) in different solvents. The structured absorption and photoluminescence (PL) spectra of the PDI in the polymer are sensitive to the solvents. The excited states with the PL peaks at 530 and 570 nm have the same PL excitation bands and life times, but the PL excitation band of the 625 nm excited states with long life time is different from the others. The PL bands with the peaks at 530 and 570 nm originate from the separated PDIs, whereas the 625 nm emission band is connected with the - stacked aggregates of the PDI in the polymer. The polymer chains become coiled to be favor of forming the - stacked aggregates of the PDI in weak polar solvent. The experimental results indicate that more - stacked aggregates are formed in tetrahydrofuran/ethanol blend solvents due to the collapsed polymer chains, but the PL intensity of the aggregates is precipitately decreased with the increase in the content of ethanol due to concentration quenching. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4113-4118, 2013