Quercetin-3-O-fatty acid esters showed antiplatelet aggregation activity. The role of surface activity in the mechanism of action of quercetin-3-O-fatty acid esters was studied. Quercetin-3-O-fatty acid esters canform a liquid membrane by itself, and can also form a liquid membrane together with L-α-phosphatidylcholine and cholesterol. Transport of platelet aggregation inducer, adenosine diphosphate and the calcium ion across the liquid membrane formed by quercetin-3-O-fatty acid esters and quercetin-3-O-fatty acid esters with L-α-phosphatidylcholine-cholesterol was determined. The liquid membranes changed the transport of adenosine diphosphate and calcium, and indicated that the liquid membrane formed by quercetin-3-O-fatty acid esters had the effect on the mechanism of action of antiplatelet aggregation of quercetin-3-O-fatty acid esters.