Copolymers which are synthesized by oligomers or homopolymers have quasi-one-dimensional structures. A tight-binding model was suggested to study the organic quantum-well properties of triblock copolymers xPA/nPPP/yPA and xPPP/nPA/yPPP consisting of polyacetylene (PA) and poly( p-phenylene) (PPP). It was found that the electronic density in the lowest conductive state (LU-MO) could be tuned by the ratios of homopolymers and interfacial coupling. The spontaneous quantum tunneling effects will occur in triblock copolymer xPA/nPPP/yPA with the increasing interfacial coupling. Copolymers which are synthesized by oligomers or homopolymers have quasi-one-dimensional structures. A tight-binding model was suggested to study the organic quantum-well properties of triblock copolymers xPA / nPPP / yPA and xPPP / nPA / yPPP consisting of polyacetylene It was found that the electronic density in the lowest conductive state (LU-MO) could be tuned by the ratios of homopolymers and interfacial coupling. The spontaneous quantum tunneling effects will occur in triblock copolymer xPA / nPPP / yPA with the increasing interfacial coupling.