An electronic device case and a decorative film thereof are provided. The decorative film includes a plurality of stacked optical layers. Each of the plurality of stacked optical layers includes a first optical layer, a second optical layer formed on the first optical layer, a third optical layer formed on the second optical layer, and a fourth optical layer formed on the third optical layer. The refractive indices of the first optical layer, the second optical layer, the third optical layer, and the fourth optical layer vary according to a predetermined rule, and the refractive indices of the first optical layer, the second optical layer, the third optical layer, and the fourth optical layer are all between 1.40 and 1.70. The first optical layer and the third optical layer have different refractive indices, and the second optical layer and the fourth optical layer have the same refractive index.