Cracked lips in the middle of the mouth has not healed to consider the physiological factors, but also may be allergies, lipitis and other factors triggered, you can carry out general treatment or drug treatment. 1. Physiological factors, if you often drink less water or often in too dry environment, may lead to the middle of the lips cracked mouth has not healed, you can carry out physical conditioning, such as drinking more warm water, appropriate physical activity, eat more vegetables and fruits. 2. Allergy, if contact with allergy-prone substances, produce allergic reaction, may lead to this symptom, can be under the guidance of the doctor to use anti-allergy drug treatment, such as Chlorotetracycline, Dicetirizine and so on. 3. Lipitis, if there is a lipitis, may lead to lip skin damage, so there will be a crack in the middle of the lip has not been healed symptoms, you can use erythromycin ointment, pimecrolimus, tacrolimus and other drugs to treat. Usually it is best not to use drugs blindly, so as not to lead to the aggravation of symptoms. Use drugs under the guidance of a physician.