Highly ordered arrays ofCo100-xWx(0≤Χ≤8)nanowires (NWs) with diameters of∼35 nmwere fabricated by co-electrodeposition of Co and W into pores ofanodized aluminum oxide (AAO) templates. The effect of adding tungsten to cobaltNWs and as well as the thermal annealing effect on the magnetic properties and structural of the NWs were explored. Morphology of samples was studied by a scanning electron microscope (SEM). The magnetic properties of samples were measured by Alternating Gradiant Force Magnetometer (AGFM) at room temperature and X-ray diffraction pattern has been used to determine crystalline structure of NWs. The results show that the magnetic parameters, such as coercivity field and squareness were decreased with increasing the W content. So that,the coercivity is decreased from 1305 Oe (Co) to 840Oe. For study the effect of temperature on the magnetic properties of NWs, fabricatedNWs were annealed at different temperatures (300, 400,500, 550 and 600 ºC). It is observed that the coercivity field of all deposited NWs increases with temperature and maximum variation related to Co97W3NW from 853Oe at room temperature to 1340Oe at 600 oC.The changes in magnetic property of NWs are rooted in a competition between shape anisotropy and magnetocrystalline anisotropy in NWs.