Many babies with asymmetrical leg lines are unconsciously discovered by mothers and fathers during the bathing or nursing of their children, and babies with asymmetrical leg lines are often combined with asymmetrical hip lines. Asymmetric leg and hip lines are associated with hip dysplasia or hip dislocation, but leg and hip line asymmetry is very common, and the majority of babies have no problems, only two or three out of ten babies have problems. The incidence of hip dysplasia is only 1 to 4 per 1,000, so the misdiagnosis rate of hip dysplasia is very high with leg and hip asymmetry, so we need to do further examination for babies. Asymmetrical leg lines are a very common phenomenon in infants, but the majority of children are normal. Only a very small number of children have hip dysplasia or hip dislocation, through the ultrasound and x-ray can know whether the baby has any problems.