The concept of femoroacetabular impingement ( FAI ) was first proposed by Ganz, which had been more and more concerned in recent 10 years. FAI refers to abnormal impact or entrapment in the femoral head and neck border and in the margin of the acetabulum and the related clinical symptoms in the hip movement process caused by dysplasia of the hip joint, injuries, operation and so on. Muscular tissues around the hip joint act as the powerplant. The coordination and antagonism among muscles promote the completion of movement and the avoidance of impact in the joint, when the structures and functions of the innervation and muscles are perfect. Even in the patients with developmental or acquired abnormal anatomy, the occurrence of impact or FAI is not inevitable. Due to developmental or acquired abnormal anatomy, the imbalance of motivation functions of muscles or both abnormal structures and abnormal motivation functions, the occurrence of FAI becomes possible. The long-term, frequent and repeating impact makes the articular cartilage be further involved by injures, degeneration and stripping of the glenoid labrum, and it is hard to avoid the occurrence and development of osteoarthritis. Due to the impact in the joint, the rhythm in the corresponding direction will be certainly changed. Therefore, it is supposed that the understanding of the occurrence, development course and discipline of impact is helpful for the investigation and research of early prevention and compensation training. A long-term longitudinal survey is performed in the adolescents majoring in sports, in which some persuasive evidences may be found. Individualized diagnosis and treatment will always be the basic principle of thinking and practice in the clinical work. The etiology, pathological mechanism and prognosis of FAI should be further explored and more evidences on the basis of the evidence-based medicine should be accumulated clinically, so as to improve the understanding and prevention level of this disease.