To provide a method for preparing propylene oxide by converting propylene into propyelene oxide characterized by having excellent features by using cumene hydroperoxide as the oxygen carrier, also process to obtain propylene oxide from propylene can be conducted under high yield condition, further the burden in refining process of propylene oxide as the desired product can be decreased.

The method for preparing propylene oxide involves the following processes. Reaction process: The process for obtaining propylene oxide by reacting propylene with cumene hydroperoxide in the presence of a catalyst. Recovery process: The process in which the reaction mixture obtained in the reaction process is subjected to distillation, and the unreacted propylene is recovered from the column top of distillation column, wherein column bottom temperature of the distillation column is kept at 200°C or lower.