Abstract: Histone deacetylase 6 (HDAC6) is an unique subtype of histone deacetylases with two tandem deacetylase domains and substrate specificity for non-histone proteins. It is involved in many important physiological and pathological processes and has become a promising therapeutic target in recent decades. Different kinds of potent HDAC6-selective inhibitors have been reported around the world. This paper reviews the progress in the study of structure and functions of HDAC6 as well as the development of HDAC6-selective inhibitors.