ZnSe nanowires (NWs) were synthesized by using a thermal evaporation method in a vacuum-sealed quartz tube inside a tube furnace. NWs were used ZnSe powder as a precursor to grow. ZnSe NWs grow on silicon (100) substrates coated with different thickness 2, 5, and 10 nm Au catalysts film. The growth mechanism of NWs is vapor-liquid-solid (VLS) mechanism. It will help us to get the good crystallinity and less defect in the NWs. Moreover, we will observe the different condition of NWs by controlling the temperature of precursor, temperature of growth area, pressure, carrier gas, thickness of Au film, position of substrate and growth time of NWs. The temperature of precursor decides the amount of the ZnSe vapor. As the temperature is higher the vapor will come out more and quickly. The temperature of growth area controls the precipitate condition of NWs. Also, pressure is one of the important condition of growing NWs. It controls the growth environment, such as the magnitude of vapor pressure. In this work, the pressure is kept around 0.4 to 1 Torr to observe the variation of NWs. Carrier gas in this work mainly affects the position of the NWs growth. However, in this work different thickness of Au film cannot be observed the obviously different dimeter. Position of substrate can show the growth area of the NWs, namely the distribution of NWs. It combines above conditions such like pressure and carrier gas. NWs in different position can grow verity of configuration or distribution. At last, growth time of NWs determine the density and length of NWs. As the time is longer, NWs will become longer and more density. Combination of above conditions, the length of appropriate NWs we need is about 20-50 μm, and the dimeter is around 80 nm. Furthermore, the morphorlogy of NWs is uniform and straight. ZnSe NWs were characterized by field-emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), and transmission electron microscope (TEM) about the morphology and crystal structure.