Abstract: Objective To evaluate the effect of tumor necrosis factor ? （TNF-?） on Nuclear Factor-κB(NF-κB) activity in cultured rats H9C2 cells. Methods H9C2 cells were cultured in vitro and treated with TNF-a , The quantitative analysis of the protein content and the DNA binding activity of NF-κB was examined by the Western blot method and electrophoretic mobility shift assay (EMSA) method. Alamar Blue assay was used to assess the proliferation of the treated cells. Results　TNF-a could active NF-κB activation pathway in rats H9C2 cells，Alamar Blue assay reveal significant difference in the absorbance between the treated cells and the control cells. Conclusion Some regulating effect of TNF-? on rats H9C2 cells might be exerted through NF-κB activation pathway.