In this study, the proteomic changes of MCF-7 cells exposed to different concentrations of cytotoxin were investigated. At different time points, differentially expressed protein families were detected in MCF-7 cells exposed to cytotoxin. At 8 h, the cytotoxin effects mainly associate with the interference of cell cycle and different intracellular pathways. Among these differentially expressed proteins, pro-apoptotic proteins were also highly expressed. At 24 h, it appeared that cytotoxin induced cell death in MCF-7 cells by involving various cell death pathways.