Disclosed herein is a conductive copolymer. The conductive copolymer can prevent water-absorbance, lower the concentration of polyacid contained in a molecule and exhibit superior film characteristics and excellent storage stability via a reduction in aggregation between molecules, as well as impart improved efficiency and lifetime to optoelectronic devices. The conductive copolymer includes a conductive polymer doped with a polyacid copolymer represented by Formula 1 below: Further disclosed are a conductive copolymer composition, a conductive copolymer composition film and an organic optoelectronic device, each including the conductive copolymer.