We investigated the temperature dependence of electrical resistance of a reactively sputtered Mo-oxide film with a composition near MoO3 and found that the sputtered Mo-oxide film shows a large electrical resistance drop of much more than 104-fold at over 350 °C. Such a large drop in electrical resistance was found to be caused by a phase transition from an amorphous state to a crystalline state. It was confirmed that a W/Mo-oxide/W device shows a typical resistive switching effect of a phase change random access memory material and exhibits reversible resistive switching by the application of unidirectional set and reset voltage. The resistance contrast of the device had a large value of about 105-106. Furthermore, the Mo-oxide film showed much better thermal stability in the amorphous state than conventional phase change materials. These results indicate that the Mo-oxide film is a promising oxide-base phase change material for phase change random access memory.