Oral sores also called oral ulcers, commonly known as mouth sores, which occurs in the oral mucosa superficial ulcers, the size can be from a grain of rice to soybean, round or oval, surrounded by congestion, ulcers have self-limiting, recurrent and cyclical. Factors that cause mouth ulcers are: first, trauma, mechanical stimulation damage to the mucosa can lead to mouth ulcers. Second, low physical quality, decreased immunity can lead to oral mucosa ulcers. Third, staying up late, smoking, alcohol stimulation can lead to oral ulcers. Fourth, excessive mental stress and depression. Fifth, the human body lacks vitamins, iron elements, zinc or folic acid. For the treatment of oral ulcers and there is no cure, all treatments are to shorten the attack period, prolong the intermittent period, patients should eat less spicy food, do not stay up all night, eat more vegetables, fruits, maintain good oral hygiene, relax.