The roots of Cynanchum caudatum M. (Asclepiadaceae) affored 21 new pregnane glycosides which had sibirigenin, cynanchogenin, gagaminin, 12-O-nicotinoyllineolon and rostratamine as the aglycone moiety and 2,6-dideoxy-3-O-methylhexopyranoses as component sugars. The structures of these compounds were elucidated by spectroscopic methods and chemical evidence.