The methanol extract from seed of Myristica fragrans (Myristicaceae) demonstrated a potent inhibition on the pro-liferation of cultured human tumor cells such as A549 (non small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system) and HCT-15 (colon) in vitro. By the continuous effort to purify the active components responsible far the anti-proliferative effect on tumor cell lines, we have isolated eleven kinds of lignan components, i. e., safrole (1), machilin A (2), licarin B (3), macelignan (4), mere-dihydroguaiaretic acid (5), mγnstargenol A (6), methoxyeugenol (7), machilin F (8), licarin A (9), nectandrin B (10), and 2-(4-allyl-2,6-dimethoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)propan-1-ol (11) together with a novel furan fatty acid, (E)-3-(3-methyl-5-pentylfuran-2-yl) acrylic acid (12) from seed extract of M. fragrans. Chemical structures of the isolated components (1-12) were established bγ the aid of NMR spectroscopic analyses, i. e., COSY HMQC and HMBC. Each of the Isolates demonstrated a potent inhibition on the proliferation of cultured human tumor cells such as A549 (non small cell lung), SK-OY-3 (ovary), SK-MEL-2 (melanoma) and HCT-15 (colon) in vitro.