Hereditary spinocerebellar ataxia type 17 (SCA17) is an autosomal dominantly inherited progressive degenerative disease of the nervous system. Also known as Huntington's disease-like 4(HDL4), SCA17 mainly features ataxia, muscle dystonia and psychiatric symptoms. The gene predisposing to SCA17 has been mapped and cloned, which encodes a TATA-binding protein (TBP). A CAG repeat expansion in the coding region of TBP gene can cause polyglutamine chain extension in the protein. This paper reviews recent progress in the research on SCA17 in regard to its clinical, etiology, pathology and pathogenesis.