Transient synovitis of the hip joint in children was first described by Lovett and More in 1892and is the commonest cause of painful hip in children. It is characterized by pain and limp of acute onset, generally shart-lived, unassociated with structural changes in the femoral capital epiphysis demonstrable roentgenographically.. The pathology is of interest, not because it is a disabling condition, but because of the difficulties in differentiating it from more serious disease of the hip such as Legg-Calve-Perthes disease, tuberculosis, osteomyelitis and etc. The 76 cases so diagnosed at the Han-II hospital from 1974 to 1983 were reviewed and reported as follows; 1. There was probably associated with predisposing factors such as infection, and trauma. 2. The diagnostic criteria were clinical symptoms, laboratory and radiological findings. 3. The treatment was bed rest, skin traction on the affected leg, non-weight bearing, antibiotics, sedatives and in a few cases, INH was administrated for the prevention of the tuberculosis. 4. Four hips among them revealed later as Legg-Calve-Perthes disease and tuberculous arthritis of the hip joint.