Four new endiandric acid analogues, tsangibeilin C (1), tsangibeilin D (2), tricyclotsangibeilin (3) and endiandric acid M (4), one new lignan, beilschminol B (5) and two new sesquiterpenes, (+)-5-hydroxybarbatenal (6) and (4R,5R)-4,5-dihydroxycaryophyll-8(13)-ene (7), together with four known compounds (8-11), were isolated from the roots of Beilschmiedia tsangii (Lauraceae). The structures of 1-7 were determined by spectroscopic techniques. Among the isolates, endiandric acid M (4) exhibited moderate iNOS inhibitory activity, with an IC50 value of 31.70 mu M.