A new dammarane-glycoside, ginsenoside Rz1 (1), was isolated from heat-treated Panax ginseng C. A. MEYER (Araliaceae) with ginsenosides Rk1 and Rg5. The structure of 1 was established to be (Z)-12beta-hydroxydammara-20(22),24-dien-3beta-yl O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucospyranoside by spectroscopic means. HPLC analyses revealed that the ginsenosides Rz1, Rk1, and Rg5 were present in the ratios of 1 : 2 : 6, respectively.