Sodium ferulate (SF) is one of the antiplatelet ingredients in Radix Angleica sinensis. The effect of SF on 14C-arachidonic acid metabolism in washed intact rabbit platelets was studied with radiochromatography and radioautography. SF (0.1-3.2 mmol/L) inhibited the generation of platelet thromboxane B2 in a dose-dependent manner (reduced by 16.7-93.8%) and the IC50 was shown to be 0.762 mmol/L. Simultaneously with the reduction of TXB2 generation, the formation of PGE2 and PGF2 alpha was also reduced significantly after treatment with SF. Using radioimmunoassay SF (0.145-2.32 mmol/L) was found to inhibit rabbit platelet TXB2 formation in a dose-dependent manner. SF (0.58-2.32 mmol/L) also suppressed aortic tissue 6-keto-PGF1 alpha generation in rabbits. At the same concentrations the inhibitory effect of SF on platelet TXB2 formation was greater than that on aortic tissue 6-keto-PGF1 alpha generation. These results indicate that the cyclo-oxygenase activity may be inhibited by SF.