Catalytic synthesis and properties of β-Ga2O3 nanowires grown by metal organic chemical vapor deposition are reported. Au, Ni and Cu catalysts were suitable for the growth of Ga2O3 nanowires under our experimental conditions. The Ga2O3 nanowires grown by using Au, Ni and Cu catalysts showed different growth rates and morphologies in each case. We found the Ga2O3 nanowires were grown by the Vapor-Solid (VS) process when Ni was used as a catalyst while the Vapor-Liquid-Solid (VLS) was a dominant process in case of Au and Cu catalysts. Also, we found the Ga2O3 nanowires showed different optical properties depend on catalytic metals. On the other hand, for the cases of Ti, Sn and Ag catalysts, Ga2O3 nanowires could not be obtained under the same condition of Au, Cu and Ni catalytic synthesis. We found that these results are related to the different characteristics of each metal catalyst, such as, melting points and phase diagrams with gallium metal.