In these days, many types of researches have been performed to enhance the oxidation resistance of a zirconium alloy during an accident such as a loss of coolant accident. The pre-oxidation of a zirconium alloy is one of the solutions to enhance the oxidation resistance of a zirconium alloy. Most of the previous studies focused on the pre-oxides created at the normal operating temperature (~360 °C). In this study, the pre-oxidation was conducted at 1200 °C steam condition. Through the analysis, it was found that the high-temperature pre-oxide enhances the oxidation resistance much more significantly than the pre-oxides formed at the normal operating temperature.