Asymmetry of leg lines in babies may be due to obesity, but it may also be due to other reasons, such as hip dislocation. 1. Obesity: The asymmetry of hip and buttock lines as well as leg lines in newborn babies is mostly caused by obesity and the uneven distribution of fat in their legs. The asymmetry of leg lines caused by this condition is physiological and can be gradually reduced with time and age. 2. Hip dislocation: if the baby appears in addition to the asymmetry of the leg lines, such as the double lower limbs are not equal in length, unilateral or bilateral limitation of hip activities, or even limp, etc., this situation may be the emergence of hip dislocation, which is often manifested in the hip joint asymmetry. If the baby has the above conditions, it is recommended to go to the hospital in time, after a clear diagnosis by the doctor to formulate an individualized corrective program, so as not to delay the condition.