Objective: The aim of the study was to investigate the effect of Casticin (CAS) combination with Cisplatin (DDP) in sub-toxic concentration on apoptosis of human ovarian cancer HO-8910 cells in vitro and unravel the associated mechanisms. Methods: Human ovarian cancer HO-8910 cells were cultured in vitro. The inhibitory effect of CAS combination with DDP in sub-toxic concentration on viability of human ovarian cancer HO-8910 cells was evaluated by the MTT assay. Morphological changes of cell apoptosis were detected by Hoechst 33258 staining assay. Cell apoptosis rate was analyzed by flow cytometry. The protein expression level was analyzed by Western blot. Results: CAS in sub-toxic concentration and DDP in sub-toxic concentration could slightly inhibit Human ovarian cancer HO-8910 cells, but CAS combination with DDP in sub-toxic concentration significantly inhibited the growth of HO-8910 cells, and growth inhibition rate was increased drastically compared with the control group (P﹤0.01), and the inhibiting effect showed synergistic action. Human ovarian cancer HO-8910 cells showed the typical morphological changes of apoptosis and apoptosis rate markedly increased when they were exposed to CAS combination with DDP in sub-toxic concentration for 48 h. Western blot showed that the expression of bcl-2 protein was down-regulated and protein level of caspase-3 was activated by CAS combination with DDP in sub-toxic concentration. Conclusion: CAS combination with DDP in sub-toxic concentration could inhibit the cells growth and lead to cell apoptosis in human ovarian cancer HO-8910 cells. And the down-regulation of bcl-2 protein expression and activation of caspase-3 protein might contribute to CAS combination with DDP in sub-toxic concentration in human cancer HO-8910 cells. Objective: The aim of the study was to investigate the effect of Casticin (CAS) combination with Cisplatin (DDP) in sub-toxic concentration on apoptosis of human ovarian cancer HO-8910 cells in vitro and unravel the associated mechanisms. Methods: Human ovarian The inhibitory effect of CAS combination with DDP in sub-toxic concentration on viability of human ovarian cancer HO-8910 cells was evaluated by the MTT assay. Morphological changes of cell apoptosis were detected by Hoechst 33258 Stain assay. Cell apoptosis rate was analyzed by flow cytometry. The protein expression level was analyzed by Western blot. Results: CAS in sub-toxic concentration and DDP in sub-toxic concentration could slightly inhibited Human ovarian cancer HO-8910 cells, but CAS combination with DDP in sub-toxic concentration significantly inhibited the growth of HO-8910 cells, and growth inhibition rate was increased drastically compared with the control group (P <0. 01), and the inhibiting effect showed synergistic action. Human ovarian cancer HO-8910 cells showed the typical morphological changes of apoptosis and apoptosis rate markedly increased when they were exposed to CAS combination with DDP in sub-toxic concentration for 48 h. Western blot showed that the expression of bcl-2 protein was down-regulated and protein level of caspase-3 was activated by CAS combination with DDP in sub-toxic concentration. Conclusion: CAS combination with DDP in sub-toxic concentration could inhibit the cells growth and lead to cell apoptosis in human ovarian cancer HO-8910 cells. And the down-regulation of bcl-2 protein expression and activation of caspase-3 protein might contribute to CAS combination with DDP in sub-toxic concentration in human cancer HO-8910 cells .