Objective: To observe the effect of Radix Angelica and Rhizoma Ligusticum with different proportions (1 ∶0

2 ∶1

1.5 ∶1

1 ∶1

1 ∶1.5

1 ∶2

0 ∶1) extracted by different methods (by water、by ethanol、firstly by alcohol then by water) on platelet aggregation and prothrombin time (PT)

thrombin time (TT). Methods: Take blood from carotid artery of rabbit and measure the rate of platelet aggregation induced by ADP and PT

TT to compare their different effects. Results: Radix Angelica and Rhizoma Ligusticum with different proportions and preparation methods showed certain effects of anti-platelet aggregation and antithrombin (P<0.01 or P<0.05). The effect on PT and TT enhanced along with the ratio of Radix Angelica gradually increases; The platelet aggregation effect was the weakest While the ratio of Danggui-Chuanxiong was 1.5 ∶1. Compared with other extracts

the solution extracted by water showed a weaker effect of platelet aggregation

while solution extracted by ethanol showed a stronger effect on PT than TT. Conclusion: The different traditional efficacy of Radix Angelica and Rhizoma Ligusticum with different proportions and preparation methods may be related with their different effects of anti-platelet aggregation and antithrombin

their intrinsic material basis and relevant mechanism are worthy of further study.