Abstract: Objective To explore the differential expression of elastin in extracellular matrix in benign versus malignant breast lesions. Methods From May 2014 to August 2015, 49 breast tumor tissue specimens from 49 patients who admitted to the first medical center of Chinese PLA General Hospital were collected and stained with aldehyde fuchsin. Image-Pro Plus 5.1 software was used to quantitatively analyze the expression level of elastin. Results There were twenty-six patients with malignant tumor（aging 35 years to 71 years, 46.5±7.7 years） and 23 patients with benign tumor（aging 31 years to 72 years, 38.3±11.9 years）. The major pathological type was invasive ductal carcinoma（n=18） in malignant tumors and fibroadenoma（n=12） in benign tumors. The area of elastin deposited on ECM in malignant lesions was（14 384.4±2 853.7）μm², which was significantly larger than that of benign lesions（9 257.5±2 392.8）μm²（P=0.000）. Conclusion Extra-cellular matrix components such as elastin are significant higher in malignant breast compared to benign lesions.