Three new pyranoquinoline alkaloids, simulenoline, peroxysimulenoline and benzosimuline, together with 22 known compounds, were isolated from the stem bark of Formosan Zanthoxylum simulans. Structures including zanthodioline, a known alkaloid without published data, were elucidated by spectral evidences. Among the isolates, 14 compounds showed strong anti-platelet aggregation activity in vitro. (C) 1997 Elsevier Science Ltd.