Abstract:β-xylosidases are the members of xylanases. Their functions have been recognized to degrade xylan that is the most common hemicellulosic polysaccharide. In recent years, some microbial β-xylosidases show the function of bioactive substances transformation, including transxylosylation and dexylosylation of xylosylated substances such as notoginsenosides R1 and R2, astragaloside IV, 7-xylosyl-10-deacetylpaclitaxel and anthocyanins to produce bioactive substances. These β-xylosidases have huge potential applications in food, pharmaceutical and many other industries. Furthermore, some mechanisms involved in bioactive substances transformation by β-xylosidases have been revealed. This review mainly introduces the bioactive substances transformation functions, sources, family classification, transformation mechanisms and applications of β-xylosidases. The aim of the review is to provide useful information for the further development and utilization of β-xylosidases.