Abstract: We study systematically structural and electronic properties of ZnO/ZnS superlattice nanowires and core-shell structural ZnO/ZnS nanowires with first-principles calculations. Relaxed structures of these heterostructural nanowires are found similar to those of homogeneous ZnO and ZnS nanowires. Band structures of heteronanowires show that they are direct-band gap semiconductors. For ZnO/ZnS superlattice nanowires, bands become flatter with the formation of minibands. For core-chell ZnO/ZnS nanowires, PDOS show that they are type-Ⅱ heterostructures. These may be important in understanding structural and electronic properties of heterostructural nanowires and their utilization in electric generator and photovoltaic devices.