Lattice vibration in one-dimensional copolymer chains was studied in the framework of a tight-binding model including the interfacial coupling between homopolymer segments. The vibration density of states was obtained numerically and the characteristic of the vibration modes was recognized. It was found that there exist two types of modes, confined and hybridized. Interface modes might appear at a strong interfacial interaction. The characteristic of the organic quantum well or superlattice of a copolymer chain was discussed from the point of the lattice vibration. (c) 2004 Elsevier B.V. All rights reserved.