Molybdenum trioxide (MoO 3 ) is an interesting material for smart windows, electrodes for batteries, and gas sensors. So far, it is known that the growth of large single crystal of MoO 3 is elusive because of the rapid changing of activation energy at 650°C. Small MoO 3 crystals can be made by sublimation. In this study, we successfully grew large MoO 3 single crystals through the modified vertical Bridgman method, which can prevent the sublimation of MoO 3 . Similar structural and optical properties were measured like those of nano/ micro-crystalline MoO 3 . This study can provide evidence to contribute to the creation of large single crystals, which have a lower sublimation temperature than melting temperature.