A 0.6 centimeter mouth ulcer is not considered serious, but it is more serious if it is persistent and frequent over a long period of time. Mouth ulcers are ulcerative injuries that occur at the oral mucosa. It has more factors and triggers, including local trauma, changes in hormone levels, genetic factors, immune factors and other related. It manifests as localized burning pain, and in severe cases, it may affect eating and speaking, etc. It may be complicated by bad breath, pharyngitis, fever, and enlarged lymph nodes. Treatment is mainly to eliminate the cause of the disease, symptomatic treatment. Mild mouth ulcers are generally based on local anti-inflammatory, such as lidocaine gel, ice borax, watermelon cream and so on. But long-term recurrence of the need for local treatment at the same time systemic conditioning, such as taking immunosuppressants, such as transfer factors. However, all drugs should be used in accordance with medical advice. It is recommended to consume more vitamin-rich vegetables and fruits in daily life. Reduce the intake of spicy and irritating foods. Repeated episodes of mouth ulcers should seek medical attention.