Breast cancer, the most common cancer in the women, is the leading cause of death. Necrotic signalingpathways will enable targeted therapeutic agents to eliminate apoptosis-resistant cancer cells. In the presentstudy, the effect of shikonin on the induction of cell necroptosis or apoptosis was evaluated using the T-47D breastcancer cell line. The cell death modes, caspase-3 and 8 activities and the levels of reactive oxygen species (ROS)were assessed. Cell death mainly occurred through necroptosis. In the presence of Nec-1, caspase-3 mediatedapoptosis was apparent in the shikonin treated cells. Shikonin stimulates ROS generation in the mitochondriaof T-47D cells, which causes necroptosis or apoptosis. Induction of necroptosis, as a backup-programmed celldeath pathway via ROS stimulation, offers a new strategy for the treatment of breast cancer.