The synthesis and characterization of poly(ethylene oxide)b-poly(4-butyltriphenylamine)-b-(polyethylene oxide) triblock copolymers (PEO-b-PBTPA-b-PEO) with different block ratio are described. The optical properties of block copolymers were investigated by UV-vis absorption, and photoluminescence (PL) spectroscopy. From atomic force microscopy (AFM) observation of the annealed thin films of block copolymers, microphase-separated morphology was observed.