Tacrolimus belongs to the calcium-modulated phosphatase inhibitor, belongs to the immunosuppressant, clinically there are oral and topical dosage forms, dermatology more commonly used in topical drugs, can be used for atopic dermatitis intermittent or long-term topical treatment, which has a localized immune, inhibitory anti-inflammatory effect, topical drug action is similar to the intermediate-acting hormones, but without the side effects associated with hormones. In addition to atopic dermatitis, it is also used clinically for the treatment of facial eczema, dermatitis, psoriasis, or special areas, such as the scrotum, thin and tender skin areas of dermatitis and eczema. Tacrolimus topical treatment should be careful to first topical trial, because tacrolimus will be skin irritation, apply if there is no reaction or adapt to it before expanding the area of use.