The prognosis of nasopharyngeal carcinoma (NPC) is still poor. Trichosanthin (TCS) has abortifacient, anti-virus, immunoregulation and various anti-tumor pharmacological activities, but there are no reports about its effect on NPC and the exact mechanisms that TCS inhibits tumor are not well known. In this study, the proliferation, apoptosis and soft agar colony formation abilities of CNE2 cells were examined with various assays in vitro followed by treatment with TCS. Furthermore, the activation status of Notch signaling pathway in TCS and control cells also was examined. The results revealed that TCS could inhibit NPC cell line CNE2 in vitro, reduce clone formation ability and induce apoptosis of CNE2 cells. Down-regulation of Notch signaling may be one of the mechanisms that TCS inhibits NPC.