Aim To screen the differently expressed genes in ruptured abdominal aorta aneurysm(RAAA) using cDNA microarray. Methods 6 RAAA or abdominal aorta aneurysm(AAA) specimen were collected respectively,and total RNA was isolated from the tissues and purified to mRNA by oligotex.Both mRNA from AAA and normal aorta were reversely transcribed to cDNA with the incorporation of fluorescent dUTP to prepare the hybridization probes,then the mix probes were hybridized to cDNA microarray of 4 096 human genes.After washing,the cDNA microarray were scanned for the fluorescent signals and showed differences between 2 tissues. Northern and Western blot were used to identify the differently expression of some genes in RAAA. Results Among 4 096 target genes,124 genes were showed in differential expressed profile with 89 upregulated and 35 downregulated genes,and all 6 AAA samples were 29 genes upregulated and 13 downregulated.The differential expressed genes involved in the functions of matrix metalloproteinases(MMP),inflammation,apoptosis,signal conduct,proto-oncogene and anti-oncogene,which meant that they had potential value in the pathogenesis of AAA.Then,Northern and Western blot were used to identify the different expression of MMP-9 and tissue inhibitors of metalloproteinase-2(TIMP-2) in RAAA. Conclusion The investigation based on cDNA microarray in researching related genes in RAAA afforded a new idea in studying pathogenesis,prevention and therapy of RAAA.