Funnel chest is a congenital and often familial disorder with a navicular or funnel-shaped appearance, mainly due to the overgrowth of rib cartilage on both sides of the sternum after growth and development begins, resulting in the formation of an inward depression of the sternal body (especially the root of the saber process) and its corresponding 3rd to 6th rib cartilage on both sides. In infancy and early childhood, this often appears as a mild case of funnel chest, which is not recognized by the parents and is promptly seen in the hospital. Parents must pay more attention to the development of the child’s thorax and go to the hospital in time to avoid the emergence of other comorbidities such as scoliosis and the loss of the best time for treatment. The majority of children with funnel chest are found clinically when they have shortness of breath after activity or during physical examinations at school, and although they can still be treated, they lose the best treatment age of 4 to 5 years old. As the father and mother of a child, please observe the development of the child’s chest more often when bathing him/her after the age of 3.