【Abstract】ObjectiveTo investigate the effects of As2O3 on expression of NF-κB p65, survivin and caspase-3 in human breast infiltrating duct carcinoma xenograft model on nude mice. Methods A human breast infiltrating duct carcinoma model on nude mice was established and the nude mice were divided randomly into three groups: control group, DDP group and As2O3 group （1.5 and 3.0 mg/kg concentrations）. The expression of survivin mRNA was detected with the method of in situ hybridization and the expressions of NF-κB p65, survivin and caspase-3 protein were measured with immunohistochemistry. ResultsThe positive rates of NF-κB p65 and survivin expression were higher in the control group than those in the DDP group and the As2O3 groups, but that of caspase-3 was on the opposite way (P＜0.01). The positive rates of NF-κB p65 and survivin in As2O3 group were negatively related with the concentrations of As2O3 (P＜0.01), but that of caspase-3 was on the opposite way (P＜0.01). The expressions of NF-κB p65 and survivin protein were positively correlated with that of survivin mRNA, but any of them was negatively correlated with the expression of caspase-3 protein. ConclusionAs2O3 inhibites survivin probably by inhibiting the activity of NFκB p65 and subsequently activates caspase-3, which induces apoptosis of human breast infiltrating duct carcinoma cells and is in a dose-dependent manner.