To study the synergistic anticancer effect of Z18 combined with S8 in vitro against HeLa cell, we firstly determined the cell death rate using the trypan blue exclusion method and the necrotic cell death was identified by flow cytometry. After being confirmed the autophagy induction in Z18-treated cells, we next analyzed LC3-II conversion by the western blotting and used GFP-LC3 or mRFP-EGFP-LC3 expressing cells to check the autophagic activity and the autophagic flux after the combination treatment. Finally, we inhibited the autophagic activity or the autophagic flux by using ATG5 siRNA or CQ and determined the cell death rate after the combination treatment. It is shown that the pharmacologic inhibitor of Fatty Acid Synthase (FAS) S8 would promote the Z18-mediated cell death in HeLa cells (P<0.05) with the increase of the concentration of S8 and the cell would die mainly as a result of necrotic processes. However, when Z18 is combined with S8, S8 has no effect on the autophagic activity induced by Z18, such as LC3-II conversion. Inhibited autophagic activity has no effect on the cell death after the combination treatment. It is suggested that S8 does not change the autophagic activity but increase the cell death rate in HeLa cells. The enhancement of Z18 anti-tumor activity by S8 may be through another pathway of cell necrosis, and is not related to the autophagy pathway.