To study the effect of Saponins of asparagus on HepG2 apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential (Deltapsim) levels. Saponins of asparagus with different concentration was treated with HepG2 and SGC-7901 at different time, MTT assay was used to detect inhibitory rate, fluorescence staining was used to observe apoptosis morphology, flow cytometry was used to detect apoptosis rate and cell cycle, also ROS and Deltapsim were measured by flow cytometry. The results showed Saponins of asparagus inhibited cell proliferation, the IC50 on HepG2 was 172.3 mg/L. Apoptosis morphology was observed by fluorescence microscope. The cell cycle of HepG2 was arrested at S phase, G2/M phase percent decreased. After 72 h the treated group appeared apoptosis peak, and apoptosis rate with high dose group 30.94 plusmn 1.74%; After 48 h the ROS in treated group increased with high dose group 77.7 plusmn 4.5%; and Deltapsim decreased with high dose group 77.8 plusmn 1.9%. Saponins of asparagus can induce HepG2 cell apoptosis, which is caused by increasing ROS and decreasing Deltapsim of HepG2.