Objective:To investigate the effect of exogenous SIRPα1 gene on the proliferation and apoptosis of MCF-7 and explore the molecular biology mechanism. Methods:SIRPα1 gene was transfected into SIRPα1-negative MCF-7 with lipofectamine. Cell were stimulated by EGF and the expression of JNK and pho-JNK were examined by Western blot. The proliferation activity was assessed by MTT and the apoptosis of MCF-7 was detected by TUNEL. Results:After SIRPα1 was transfected into MCF-7,there was no change of JNK protein expression but a remarkable decrease of p-JNK. In addition,the expression of SIRPα1 also reduced MCF-7 cell vitality and induced cell apoptosis. The intracellular part of SIRPα1 can be phosphorylated in response to a variety of growth factors. But there was no significant change of cell apoptosis after EGF stimulated MCF-7 which were transfected with exogenous SIRPα1 gene. Conclusion:SIRPα1 can induce cell apoptosis,inhibit cell proliferation in MCF-7 cell line and serve as a potential anti-oncogene.