The present invention relates to Rhodanobacter ginsenosidimutans KCTC22231T-derived ginsenoside glycosidase and use thereof. The polypeptide has an activity of converting PPD (protopanaxadiol)-type saponins into in vivo absorbable and highly active deglycosylated saponins, by selective hydrolysis of a bond at a particular position of ginsenoside. The present invention also relates an amino acid sequence constituting the polypeptide, a nucleic acid sequence encoding the protein, a recombinant vector comprising the nucleic acid sequence, and a transformant transformed with the vector. The invention further provides a method for preparing Rhodanobacter ginsenosidimutans KCTC22231T-derived ginsenoside glycosidase by culturing the transformant, a method for converting PPD (protopanaxadiol)-type major ginsenoside into a rare ginsenoside that is absorbable in vivo using the protein, and a composition for converting PPD-type saponins into in vivo absorbable saponins, having the protein as an active ingredient.