Thirty-eight novel butylphthalide-hydroxycinnamic acid hybrid derivatives were designed and synthesized to discover effective antiplatelet agglutination drugs. Among these compounds, 3 o gave the optimal inhibitory activity against AA-induced platelet aggregation in vitro and also exhibited better inhibition than the precursor 3-n-butylphthalide (NBP) against thrombin-induced platelet contraction, carrageenan-induced tail thrombosis, and FeCl