Asymmetry of hip lines in five-month-old babies may be caused by physiologic or pathologic factors, and the most common cause of pathologic factors is hip dysplasia. It is recommended to make a clear diagnosis after timely consultation. 1. Physiological factors: related to the baby’s obesity, some of the more obese babies, may be due to the uneven distribution of fat on both sides of the hip stripe asymmetry, is a normal physiological phenomenon, followed by dietary adjustments under the guidance of the doctor. 2. Pathological factors: hip dysplasia is a group of diseases, including acetabular dysplasia, hip subluxation or complete dislocation. This group of diseases in infants aged 0-6 months, mainly manifested as asymmetric skin folds on the buttocks and inner thighs, shortening of the affected limbs, and impaired hip abduction. It is recommended that the relevant group of people should seek timely medical treatment to determine the presence of pathological factors through imaging and physical examination, and to manage the treatment accordingly.