Objective To investigate the expression of nuclear factor kappaB(NF-κB) and regulated upon activation normal T cell expressed and secreted chemokine(RANTES) during the formatiom of ascending aortic aneurysm. Methods Forty Wistar rats were randomly divided into the control group(n=20) and the experimental group(n=20).The rat models were made by ligating the ascending aorta. The ascending aortas were taken after ligation for 3months. Immunohistochemistry staining was performed to detect the protein expression of NF-κB and RANTES. The expression of NF-κB and RANTES mRNA were detected by RT-PCR. Results Immunohistochemisry staining results showed NF-κB and RANTES expression significantly increased in aneurysm, while there was a little positive staining in the control group. RT-PCR results indicated that the expression levels of NF-κB and RANTES in the aneurysm were stonger than that of the control group. The expression of NF-κB and RANTES mRNA were remarkably correlated. Conclusion The expression of NF-κB and RANTES in ascendin aortic aneurysm are stronger than that in