An organic semiconductor polymer comprising a structural unit represented by the following Formula (I), a composition for organic semiconductor material, a photovoltaic cell and a polymer. wherein Z1 and Z2 each independently represent S, O, Se or Te; R represents —SOpX, —CN, —NO2, —P(═O)(OR1,)(OR2) or —C(R1′)═C(CN)2; X represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aromatic heterocyclic group or —NR3(R4); R1, R2, R1,, R3 and R4 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aromatic heterocyclic group; R3 and R4 may bond with each other to form a ring; and p represents 1 or 2.