ObjectiveObstructive sleep apnea hypopnea syndrome (OSAHS) is a common disease in the department of otolaryngology. The incidence of OSAHS in children is on the rise. Investigation shows that the incidence rate of OSAHS in children is 4%~5%, and 2 to 6 years old are its high ages. The peak ages of OSAHS are 6 to 12 years old. OSAHS of Children not only seriously affects children's sleep quality, but also causes a series of adverse reactions including the retardation of growth and mental. The main etiology of OSAHS in children is tonsil and/or adenoid hypertrophy, so the most effective treatment of the disease is the tonsilectomy and adenoidectomy. However, tonsils and adenoids are important components of lymphoid tissue system in children, and play an important role in the body’s defense and protection function. Whether the surgical treatment of OSAHS affects the immune function of children is controversial. Some scholars believe that the immunity of children after tonsilectomy and adenoidectomy is reduced,while others believe that the immunity of children with OSAHS remains unchanged or even improved after surgery compared with that before surgery.This article reviews the changes of the immune indexex before and after OSAHS surgery in children.