ObjectiveTo analyze the differences in proteins between aneurysm/dissection patients and healthy subjects, and subsequently figure out differential proteins related to medial degeneration of aortic aneurysm/dissection.MethodsAortic wall samples were collected from 6 male aortic aneurysm patients (an aortic aneurysm group, mean age 56.50±8.19 years), 6 male aortic dissection patients (an aortic dissection group, mean age 54.17±6.68 years) and 6 male healthy subjects (a normal group, mean age 40.50±9.31 years) between December 2019 and May 2020 in West China Hospital of Sichuan University. Quantitative proteomics was performed using tandem mass tag (TMT) techniques, followed by gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.ResultsA total of 63 differential proteins were obtained both in the aortic aneurysm group and the aortic dissection group compared with the normal group, with 30 up-regulating and 33 down-regulating. The differential proteins were involved in multiple biological processes and clusted on peroxisome proliferators-activated receptor (PPAR) signaling pathway, extracellular matrix-receptor interaction signaling pathway and complement and coagulation cascades signaling pathway.ConclusionThe identified proteins may help to demonstrate new molecular mechanisms related to medial degeneration of aortic aneurysm/dissection.