Antiproliferative activity test of octadeca-8,10,12-triynoic acid isolated from parasitic plant scurrula atropurpurea (BI) dans. Againta four kinds of human cancer cell lines, i.e: HeLa (human cervix epitheloid carcinoma, leukemia THPI, (human peripheral blood acute monocyte), carcinoma a549 (human lung carcinoma) and lymphoma HUT78 (human cutaneous T-cell lymphoma) was carried out. The result showed that octadeca-8,10,12-triynoic acid exhibits the antiproliferative activity against four kinds of human cancer cell lines with the LC value of 0.66, 0.86, 0.99 and 2.36 mg/ml for HeLa, leukemia THPI, lung carcinoma a549, and lymphoma HUT78, respectively, lower than 4 mg/ml, which is the antiproliferative activity threshold for pure isolate or compound.