Objective：To study the effects of RASSF1A gene on activity of NF-κB in human gastric carcinoma cell line SGC7901. Methods：NF-κB activity was measured by EMSA( electrophoretic mobility shift assay).Expression of P65 protein was detected by Western blotting and immunocytochemistry. Results：Compared with the non-transfected and vector transfected cells, NF-κB activity of RASSF1A-SGC7901 cells was lower. The expression of P65 protein in RASSF1A-SGC7901 cells was lower than that of non-transfected and vector transfected cells. Conclusions：RASSF1A gene could suppress the activity of NF-κB in SGC7901 cells.