Objective To investigate the molecular mechanism of rupture of aneurysm by analyzing the expression of vascular structural proteins， growth factors， and matrix proteases in one patient with intracranial aneurysm （IA） at different stages， and to provide a theoretical basis for the early screening and prevention of IA.Methods The samples of the unruptured aneurysms， the ruptured aneurysm wall， and the superficial temporal artery wall were collected from 6 patients with IA. Quantitative real-time PCR and Western blotting were used to measure the changing trends of the expression levels of three structural proteins （type III collagen， fibronectin and laminin）， two growth factors ［vascular endothelial growth factor （VEGF） and basic fibroblast growth factor （bFGF）］， and two matrix proteinases ［JNK and matrix metalloproteinase 2 （MMP2）］.Results There were high expression levels of type III collagen， laminin， bFGF， and MMP2 in the normal vascular wall samples collected from the superficial temporal artery. Most proteins showed a moderate expression level in the samples of unruptured aneurysms. After rupture of aneurysms， there were reductions in the expression levels of type III collagen and laminin and increases in the expression levels of fibronectin and VEGF. The mRNA expression levels were basically consistent with the protein expression levels.Conclusions Structural proteins and growth factors show different expression levels and patterns in normal vascular wall， unruptured aneurysm wall， and ruptured aneurysm wall. Citation:Journal of International Neurology and Neurosurgery, 2022, 49(3): 14-20.