Abstract: Eubhorbia neriifolia L. is a plant of Euphorbia family.Five known lignans were isolated from the aerial parts of E. neriifolia L. by silica gel for column chromatography and preparative high-performance liquid chromatography (HPLC).Their potential antitumor activities were evaluated in vitro.Compound 2 exhibited proliferation inhibition and cytotoxicity against esophageal squamous cancer cells, especially KYSE-410 and KYSE-450 cells.Further analyses showed that compound 2 could significantly induce apoptosis through the activation of caspase 3/9 and down-regulation of the Bcl-2/Bax protein ratio.These results suggested that compound 2 had a significant inhibitory effect on the esophageal squamous cancer cells, especially KYSE-410, which deserves further research as a potential antitumor agent.