Abstract: Phthaloyl dichloride( 1 )was reacted with LiAlSeH₂ to give benzo［c］selenophene-1, 3-dione( 2 ), which was treated with the Grignard reagents to generate hydroxyl compounds 3a-3h . These compounds were finally converted to target products 4a-4h by treatment with hydriodic acid. The structures of 4a-4h were confirmed by MS and ¹H NMR. Their inhibitory activity against adenosine diphosphate(ADP)-induced platelet aggregation was evaluated by Born′s turbidimetric assay; free radical scavenging activity was assayed by xanthine oxidasemethod and 1, 10-phenanthroline spectrophotometric method. It was found that compound 4f displayed more potent inhibitory effect on platelet aggregation than 3-n-butylphthalide and comparable hydroxyl free radical scavenging activity in vitro to that of edaravone. Therefore, compound 4f might be the candidate for further investigation.