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.