Objective    To analyze the effects of overexpressed iASPP on breast cancer cell line MCF-7.     Methods    The iASPP cDNA was obtained from breast carcinoma tissue by RT- PCR. The breast cancer cell line MCF-7 that overexpressed iASPP was established by stable transfection and G418 selection. The proliferation and apoptosis of the MCF-7 cells that overexpressed iASPP after exposure to cisplatin were detected by MTT and flow cytometry.     Results    The MCF-7 cells that overexpressed iASPP were successfully constructed. Overexpressed iASPP could significantly decrease the apoptosis rate of MCF-7 cells exposed to cisplatin and weaken the inhibitory effects of DDP on the proliferation of MCF-7 cells.     Conclusion    Overexpressed iASPP attenuates the sensitivity of human breast cancer cell line MCF-7 to cisplatin.