The study was intended to illustrate the anticoagulant activity of different part (including root,leaf and flower) of Panax notoginseng.The prothrombin time (PT) assay was introduced to evaluate the anticoagulant activity of the 70% methanol extracts of root,leaf and flower of P.notoginseng as well as the various saponins separated from the root and leaf by macroporous resin.The results were submitted as follows:(1)At the concentration of 20 mg/mL,the PT values of 70% methanol extracts of root,leaf and flower of P.notoginseng were much higher than blank control and positive control.The PT values of extracts of leaf and flower were significantly higher than that of root extract.(2)According to the test of dose-effect relationship,20(S)-protopanaxadiol saponins (PDS) separated from root (R-50,50% ethanol extract of root) and leaf (L-50,50% ethanol extract of leaf) showed a much higher PT value than that of other samples ［20(s)-protopanaxatriol saponins (PTS) separated from root (R-30) and leaf (L-30),P.notoginseng saponins (PNS) and notoginseng leaf saponins (NLS)］,especially when the concentration was under 25 mg/mL;(3)The PT value of L-50 was always higher than that of R-50 with a concentration.These results indicated that leaf and flower possess stronger anticoagulant activity among the different part of P.notoginseng.And the PDS from leaf,showed the strongest anticoagulant activity,may be the potential anticlotting drug.