Differential diagnosis should be made with the following symptoms: 1, dense bone dysplasia: the child is short, the cranial bone is enlarged, the frontal occipital bone is protruding, there are common intersegmental bones, the terminal phalanx is underdeveloped, the density of the long bone is increased but the bone marrow cavity exists, and the child is not anemic. 2.Cranial epiphyseal dysplasia: the skull bone is progressively enlarged and thickened, the bone quality is not brittle, and it is mostly manifested after the age of 5 years. 3, cranial diaphysis hypoplasia: mainly manifested as “lion face” hyperplasia, no bone destruction in other parts, poor bone shaping, widening of clavicle and ribs. 4. Neonatal osteosclerosis: usually disappears within 1 month. 5, anemia or leukemia complicated by myelofibrosis: sometimes it is difficult to identify with marble bone disease, only with the help of blood test and bone marrow puncture examination. 6, fluorosis: because fluorosis involves the skull, can also be manifested as cranial plate thickening, increased density, especially the base of the skull can appear obvious sclerosis. But fluorosis is caused by chronic fluorosis, the patient has a history of long-term exposure to fluoride or long-term drinking water fluoride exceeds the allowable amount and fluoride treatment of myeloma, osteoporosis history. Fluorosis is not as homogeneous and dense as osteomalacia, and the lesions of fluorosis are mainly in the trunk, which decreases to the limbs, and the thickening of the bone lines is mesh-like, and the ligament calcification and intercalary membrane calcification can be seen in the late stage, which does not have the above characteristics of osteomalacia. Fluorosis urinalysis fluoride up to 8mg / L or more.