Objective To determine the expression of Rho associated coiled-coil forming protein kinase 1 (ROCK1) in atherosclerotic vessel walls and its correlation with matrix metalloproteinase 2 (MMP2) and transforming growth factor 1 (TGF-β1). Methods Thirty apolipoprotein E knockout mice were selected as the experimental group and fed with high-fat diet. Another 30 C57BL/6 mice were selected as the control group and fed with ordinary diet. At the 10th, 16th, 22nd, 28th and 34th weeks of feeding, the eyeball blood samples were harvested to measure the blood lipid levels. The abdominal aorta of mice was collected as samples, and then embedded and sectioned, followed by hematoxylin eosin staining to observe the morphology of vascular wall. Immunohistochemical staining was also performed to observe the expression of ROCK1, MMP2 and TGF-β1 in vascular wall. Image Pro Plus 6.0 software was used to measure the thickness of vascular wall, plaque area, and expression levels of ROCK1, MMP2 and TGF-β1 in vascular wall. SPSS statistics 27.0 was used to analyze the experimental indicators. One-way ANOVA was used to compare among groups, and Tukey test was employed for pairwise comparison. Pearson correlation analysis and linear regression analysis were applied to analyze the relationship of ROCK1 expression with thickness of vascular wall, plaque area and MMP2 and TGF-β1. Results The mouse model of atherosclerosis was successfully established. At the 10th, 16th, 22nd, 28th and 34th weeks of feeding, the blood lipid levels were significantly higher in the experimental group than the control group (P<0.05). Since the 16th week of feeding, plaques were observed in all the blood vessels of the experimental group, and its area and vessel wall thickness were increased with the extension of feeding time (P<0.05). And the expression of ROCK1 in vessel wall was gradually elevated, and the level was positively correlated with plaque area and vessel wall thickness (r=0.821,0.730; P<0.05). Linear correlation analysis and regression analysis showed that the expression of ROCK1 with MMP2 and TGF-β1 were positively correlated (r=0.801,0.906; P<0.05). Conclusion ROCK1 is expressed in atherosclerotic vessel wall, and its expression level is elevated with the thickening of vessel wall and positively correlated with MMP2 and TGF-β1. In view of the vasospasm-causing effect of ROCK1 protein, it is suggested that atherosclerotic vessel walls may be prone to spasm, and the specific mechanism needs further study.