Abstract: Sodium ferulate is one of the constituents of Dang-Gui (Angelica sinensis). In this paper platelet aggregation was measured by turbidimetric method. TXA₂ activity was estimated by measuring the contraction of rabbit thoracic aorta and PGI₂ activity by measuring inhibition of platelet aggregation induced by ADP.Results indicate that neither platelet aggregation nor carotid arterial PGI₂-1ike substance release was affected by oral adminstration of a subthreshold dose of sodium ferulate(300 mg/kg) or a subthreshold dose of acetylsalicylic acid(10mg/kg). However, sodium ferulate in combination with acetylsalicylic acid at the same doses was shown to inhibit platelet aggregation and TXA₂-like substance release (induced by collagen) by 65% and 84%, respectively, while the production of arterial PGI₂-like substance remained unchanged.These results indicate that the combined treatment with these two drugs can potentiate the antiplatelet effects without inhibiting arterial PGI₂-1ike substance release. These data may be of value for the treatment of thrombo-embolic diseases.