Notoginseng, the root of Panax notoginseng (Burk.) F.H. Chen (Araliaceae), is a Chinese traditional medicine, which is used in both raw and processed forms due to their different pharmacological activities. Detailed chemical investigation on steamed notoginseng led to the isolation of 27 dammarane-type triterpenoids (1-27), including 4 new glycosides, namely, notoginsenosides ST-1-ST-3 and ST-5 (1-4), in addition to 3 other known compounds. Of the new compounds, 1-3 possess new aglycones. Their structures were elucidated on the basis of detailed analyses of their 1 D and 2D NMR spectra and chemical reactions. The known compounds, koryoginsenoside-R-1 (19), yesanchinoside D (20), 6 ''-O-acetylginsenoside Rg(3) (24), and 3 beta,6 alpha,12 beta-trihyclroxyclammar-20(21),24-diene (25), were isolated from notoginseng for the first time.