Under normal circumstances the sternum is too soft may be the possibility of two diseases: First, the lack of in the process of growth and development of the child, resulting in the child’s acquired calcium deficiency, calcium and phosphorus metabolism abnormalities, and the appearance of the sternum softening. Second, related to genetic factors, congenital human family metabolic lead to abnormal calcium and phosphorus metabolism, and the emergence of familial chondromalacia, it is related to congenital factors. Under normal circumstances are related to acquired factors, the lack of acquired causes abnormal calcium and phosphorus metabolism, thus appearing softening of the sternum, in order to prevent can be appropriate more sunshine supplement vitamin D, can also be appropriate calcium supplements, in addition to the necessary exercise for bone deposition is a certain help.