The redness of a circle under the baby’s lips may be due to drool rash, labyrinthitis, food allergies, which can be dealt with accordingly. 1, drool rash: baby saliva more will lead to increased secretion of salivary glands reflexively and outflow, as the skin of the mouth and lips is often stimulated by physical factors such as humidity and friction, which leads to damage to the cuticle layer of the skin, forming a circle of redness under the lips. It is necessary to wipe the saliva with a cotton cloth frequently to keep the area dry to prevent aggravation of saliva rash. Topical ointments such as comfrey oil and zinc oxide oil can be used for astringent, anti-inflammatory and anti-redness treatment; 2. Lipitis: most of the baby lipitis is caused by chronic irritation or bad habits, such as long-term licking of the lips, biting of the lips and drinking less water. It is recommended to follow medical advice to prevent infection with topical erythromycin ointment, gentamycin eye ointment, etc. If the lip infection is caused by a lack of vitamins and trace elements, attention needs to be paid to supplementing foods rich in vitamin C and vitamin B2, such as oranges and apples, which are beneficial to improving the symptoms; 3. Food allergy: after the baby can eat supplementary food, if it is allergic to supplementary food, it will also cause redness around the lips. It is recommended to go to the hospital to clarify the allergen, discontinue the complementary foods that cause allergy, and if necessary, anti-allergy treatment.