Mutism refers to a persistent refusal of children to speak in certain situations that require verbal communication, such as at school, in the presence of strangers or in crowded environments, while in other situations speech is normal. Children who have no organic lesions of the speech organs, have normal intelligence and have acquired language functions, show persistent silence under the influence of certain psychiatric factors. The reasons for this include: i. Special personality traits before the disease, such as sensitivity, vulnerability, dependence, timidity, etc., and delayed developmental maturity. Although the affected child has acquired language functions, the start of speech is significantly delayed compared to normal children. Second, psychosocial factors, early experience of emotional trauma, such as parental disharmony, parental separation and divorce, etc.