Cardiac fibrosis, a significant pathological alteration following myocardial infarction (MI), remains enigmatic with respect to the role of cardiac endothelial cells (ECs). To elucidate the proteomic shifts in cardiac ECs accompanying MI-induced cardiac fibrosis, a standard MI mice model was established through ligation of the left anterior descending branch. Following 14 days of effective modeling, we isolated primary ECs from the hearts of both sham and MI models utilizing the CD31 microbeads sorting technique. Quantitative proteomics and bioinformatics methodologies, including tandem mass spectrometry, were employed to discern proteomic alterations in the primary endothelial cells of the experimental groups. Comprehensive analyses, including Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, functional enrichment analysis, and functional enrichment cluster analysis, revealed an up-regulation of proteins associated with extracellular matrix-receptor interaction pathway in cardiac fibrosis post-MI. Subsequent Western blot analysis confirmed the up-regulation of specific proteins involved in this pathway, namely collagen type VI alpha 2 (Col6α2), vitronectin (Vtn), and integrin beta (Itgβ). We conclude that the expression levels of Col6α2, Vtn, and Itgβ in primary ECs during the early stage of cardiac fibrosis, 14 days post-MI, were significantly elevated compared to the sham group (P < 0.05). This observation suggests that ECM-receptor interaction could potentially influence the progression of cardiac fibrosis following MI.