This research aimed to isolate β‐glycosidase‐producing endophytic fungus in Panax ginseng to achieve biotransformation of ginsenoside Rb1 to ginsenoside C‐K. Of these 15 β‐glucosidase‐producing endophytic fungus isolated from ginseng roots, a β‐glucosidase‐producing endophytic fungi GE 17‐18 could hydrolyse major ginsenosides Rb1 to minor ginsenoside C‐K with metabolic pathways: ginsenoside Rb1→ginsenoside Rd→ginsenoside F2→ginsenoside C‐K. Phylogenetic analysis of ITS gene sequences indicated that the strain GE 17‐18 belongs to the genus Arthrinium and is most closely related to Arthrinium sp. HQ832803.1. Significance and Impact of the Study This is the first study to provide information of cultivable β‐glycosidase‐producing Endophytic fungus in Panax ginseng. The strain GE 17‐18 has potential to be applied on the preparation for minor ginsenoside C‐K in pharmaceutical industry. Significance and Impact of the Study: This is the first study to provide information of cultivable β‐glycosidase‐producing Endophytic fungus in Panax ginseng. The strain GE 17‐18 has potential to be applied on the preparation for minor ginsenoside C‐K in pharmaceutical industry.