In this study, we evaluated the antiproliferative effects of Panax notoginseng, ginsenoside Rb1, andnotoginsenoside R1 in the human breast carcinoma MCF-7 cell line. Our results indicated thatboth Panax notoginseng radix extract (NRE) and Panax notoginseng rhizoma extract (NRhE) possesssignificant antiproliferative activities in MCF-7 cells. Compared to control group (100%), at theconcentrations of 0.05, 0.5, and 1.0 mg/ml NRE, cell growth was concentration-dependentlyreduced to 81.0 ± 6.1 (P < 0.01), 34.2 ± 4.8 (P < 0.001), and 19.3 ± 1.9 (P < 0.001), respectively.Similar results with NRhE at concentrations of 0.5 and 1.0 mg/ml were obtained in these MCF-7cells. To identify the responsible chemical constituent, we tested the antiproliferation effects oftwo representative saponins, ginsenoside Rb1 and notoginsenoside R1, on the MCF-7 cells. Thedata showed that ginsenoside Rb1 was endowed with antiproliferative properties, whilenotoginsenoside R1 did not have an inhibitory effect in the concentrations tested. Our studiesprovided evidence that Panax notoginseng extracts and ginsenoside Rb1 may be beneficial, asadjuvants, in the treatment of human breast carcinoma.