Lymph nodes are normal immune organs of the body and never disappear, only in size. The age at which lymph nodes behind the ears of young children generally become smaller depends mainly on the nature of the lymph nodes and the specific situation of the child, and cannot be generalized. Lymph nodes develop rapidly within the first year of life and may be palpable in superficial areas of a healthy child’s body, such as behind the ear, and are generally no larger than the size of a soybean, soft and mobile, and their time to disappear varies from person to person. They usually become progressively smaller as the child ages, but there is no clear clinical timeframe for their disappearance. If the swollen lymph node is caused by an infection or other disease and is palpable behind the ear in a young child, is firm and less mobile, and is accompanied by significant pressure or tenderness, the time to resolution will depend on the treatment of the specific condition. If lymph nodes are found behind the ears of young children, parents are advised to take their children to the pediatric department of a regular hospital for examination, except for other diseases, to avoid delaying the condition.