Abstract: Objective To study the antithrombotic mechanism of double the acid, safflor yellow and compatibility preparation with different ratio. Methods To observe the effect of double the acid, safflor yellow and compatibility preparation on mouse's blood clots piece of dissolving rate. ELISA was used to measure the rats’ plasmic TXB2、6-K-PGF1a、PGE2 of each group. Results The blood clots piece of dissolving rate increased in treated group. The plasmic level of TXB2、PGE2 of treated group was distinctively reduced, 6-K-PGF1a increased. And compatibility groups' effect better than double the acid and of safflower yellow pigment grain themselves.Conclusion Double the acid, safflor yellow and compatibility preparation play a role of antithrombotic, and the action after compatibility higher than its role alone.