PROBLEM TO BE SOLVED: To provide a false composition of odor of hair permanent treatment which can evaluate a masking or deodorizing effect of odor of hair permanent treatment exactly and simply, and to provide an evaluation method of a masking or deodorizing effect of hair permanent odor using this.SOLUTION: The invention provides a false composition of odor of hair permanent treatment containing dimethyl diselenide and/or methyl methylthio selenide.