(3‐(2‐Benzotriazolovinyl)thiophene (BVT) containing an electron‐transporting moiety was polymerized through FeCl3 oxidation. In addition, BVT was copolymerized with different functional groups: 3‐octylthiophene (OT) containing alkyl groups for improving the solubility in common organic solvents; N‐octylcarbazolylene (OcCz) containing hole‐transporting groups for improving the optical property; and the alkyl groups for improving the solubility. Soluble π‐conjugated poly(3‐(2‐benzotriazolovinyl)thiophene‐co‐3‐(2‐benzotriazoloethylthiophene)‐co‐N‐octylcarbazolene) ([(BVT) n ‐(BET) m ‐OcCz2 ) y ) copolymer was synthesized. 1H NMR analysis was used to verify the structure of the polyBVT copolymers. Especially, the emission of the ([(BVT) n ‐(BET) m ‐OcCz2 ] y ) copolymer (662 nm) was red‐shifted by about 64 nm, compared to that of poly(3‐(2‐benzotriazolo‐ethyl)thiophene) (polyBET, 598 nm).