Ten new guaiane type sesquiterpene lactones, namely, eupalinilides A-J (1-10), as well as nine known compounds, eupachinilide C (11), eupachifolin D (12), eupachinilide E (13), 2alpha-hydroxyeupatolide (14), 3-deacetyleupalinin A (15), heliangine (16), 8beta-tigloyloxy-2,3-seco-6betaH,7alphaH-helianga-4Z,11(13)-diene-3,10beta;6, 12-diolid-2-oic acid (17), 8beta-(4'-hydroxytigloyloxy)-3beta,14-dihydroxy-6betaH,7alphaH-germacra-1(10)Z,4Z,11(13)-trien-6,12-olide (18), and 8beta-tigloyloxy-3beta,14-dihydroxy-6betaH,7alphaH-germacra-1(10)Z,4E,11(13)-trien-6,12-olide (19), were isolated from the whole plant of Eupatorium lindleyanum. Eupalinilides B (2), C (3), E (5), F (6), and I (9) have been tested for cytotoxicity against P-388 and A-549 tumor cell lines. The results showed that eupalinilides B (2) and E (5) demonstrated potent cytotoxicity. The structures of these compounds were determined by spectroscopic methods including 1D and 2D NMR spectra.