One new lignan, trichobenzolignan (1), and seven known compounds, ligballinol (2), (-)-pinoresinol (3), ehletianol C (4), luteolin 7-O-β-D-glucopyranoside (5), chrysoeriol-7- O-β-D-glucopyranoside (6), 10α-cucurbita-5,24-dien-3β-ol (7), and arvenin I (8). Their structures were established on the basis of spectral and chemical evidence, which were in agreement with those reported in literature. The cytotoxic activities of these compounds were evaluated on four cancer cell lines such as A-549 (human lung cancer), HT-29 (human colon adenocarcinoma), OVCAR (human ovarian carcinoma), and MCF-7 (human breast cancer). As the results, compound 7 showed significant activity on HT-29 and OVCAR cancer cell lines with IC50 of 4.1 and 6.5 µM, respectively. Compounds 1, 5, 6, and 8 exhibited moderate activities in all cancer cell lines with IC50 ranging from 11.3 to 42.8 µM.