Trichosanthin (TCS) exhibits an anti-cancer effect on various human cancer cells. However, the mechanism of anti-cancer effect at the molecular level remains to be elucidated. In this study, the underlying anti-cancer mechanism of TCS in human ovarian cancer cells (OVCAR-3) was investigated using various molecular biology techniques, such as flow cytometry, western blotting. We major focus on the potential roles of apoptosis and autophagy in TCS inhibition of human ovarian cancer cells. The results demonstrated TCS inhibits human ovarian cancer cells growth due to apoptosis and autophagy. TCS triggers autophagy firstly, which was confirmed by an increased ATG5 expression and promoted LC3 cleavage, and subsequent apoptotic cell death. The apoptotic cell death induced by TCS was attenuated by both pharmacological and genetic inhibition of autophagy. The autophagy inhibitor 3-MA, which functions at the early stage of autophagy, significantly reduced TCS-induced cell death and caspase-3 activity in human ovarian cancer cells. We also demonstrated that inhibition of apoptosis had no effect on TCS-induced autophagy in OVCAR-3 cells. In conclusion, we found that a common pathway between autophagy and apoptosis exists in TCS-induced cell death in human ovarian cancer cells, which might shed light on drug therapy.