Retinoic acid ointment, also known as retinoic acid ointment, is a topical medication for the skin that induces epidermal proliferation and promotes epidermal cell differentiation, which can significantly inhibit the production of acne. By regulating the differentiation process of the epithelial cells of the sebaceous glands of the hair follicles, it has an exfoliating effect. It can also prevent as well as eliminate the skin lesion effect of acne, and is mainly used clinically for the treatment of common acne, especially acne and blackhead lesions. It is also effective in the treatment of senile, solar and drug-induced skin atrophy, and can be used for ichthyosis, psoriasis and other various keratosis abnormalities, as well as hyperpigmented skin diseases. It should be noted that this is a topical medication for the skin and is therefore recommended for use on the skin, away from the eyes, and not recommended for use on the folds of the skin. Simultaneous use with other medications that cause skin irritation and breakage, or with cosmetics or cleansers should be avoided during use to avoid aggravating skin reactions. In addition, sunlight can aggravate the skin irritation of retinoic acid and cause its breakdown. Therefore, it is recommended to avoid sunlight as much as possible during the use of this medication, and it is recommended to apply it at night or before bedtime, and it should not be applied on a large area. In conclusion, retinoic acid ointment is a topical skin medication that is mainly used to treat acne and other skin keratosis abnormalities caused by various reasons.