Seven new protopanaxatriol type saponins, 20S-sanchirhinosides A1 (1), A2 (2), A3 (3), A4 (4), A5 (5), and A6 (6), and sanchirhinoside B (7) were obtained as minor constituents from the root extract of Panax notoginseng (Burkill, F. H. Chen), which showed protection effects against antimycin A induced mitochondrial oxidative stress. Their structures were elucidated by chemical and spectroscopic methods (IR, HRESI-TOF-MS, 1D and 2D NMR). Among them, compounds 4, 6 and 7 showed significant protective effects against antimycin A-induced L6 cell injury.