This article summarizes Professor Shang Lili's experience in diagnosing and treating recurrent respiratory tract infections(RRTIs)in children based on the theory of"internal deficiency and external injury".Professor Shang believes that children are in the stage of growth and development,with delicate organs and insufficient vital energy,which is called"internal deficiency";external pathogens repeatedly invade the human body,resulting in clinical manifestations of both cold and heat,ultimately damaging the body's qi,blood,essence,and spirit,known as"external injury"."Internal deficiency and external injury"leads to repeated infections of pathogens in children and causes physical and mental distress,affecting their growth and development.The theory of"internal deficien-cy and external injury"emphasizes the influence of internal and external factors on RRTIs in children,reflecting the evolution of patho-genesis and guiding clinical staging treatment.During the acute infection period,the treatment of wind heat syndrome is based on the Xin Liang and Qing San methods,while the treatment of wind cold syndrome is based on the Xin Wen and Kai Bi methods.For the mixed deficiency and excess syndrome,various methods such as attacking,supplementing,harmonizing,and supporting should be used,and treatment should be based on syndrome differentiation,with adjustments made according to the symptoms;during the inter-mittent period of infection,Professor Shang aims to assist the righteous qi,taking into account the upper,middle,and lower Jiao,and adopting treatment principles such as nourishing the lungs,spleen,and kidneys.Professor Shang's experience provides useful ideas and methods for the treatment of RRTIs in children.