Hereditary multiple exostoses (HME) is an autosomal dominant genetic disease characterized by multiple benign cartilage-capped tumors primarily at the juxta-epiphyseal region of the long bone or on the flat bones. Because the tumor can interfere with normal epiphysis, it causes bone deformities. The clinical features include short stature, the mechanical axis deviation, and function impairment. Recent studies showed that EXT gene mutation was associated with HEM. The EXT gene was involved in the biosynthesis of heparin sulfate. The gene mutations resulted in abnormal chondrocyte differentiation. This paper reviews the research progress in clinical manifestation, pathogenesis, biochemistry, the genotype-phenotype correlations, and treatment in HME.