Objective: To investigate the correlation between quantitative parameters of ultrasound elastic imaging and clinical stage and pathological molecular classification of benign and malignant breast tumors. Methods: 85 patients with breast mass admitted to our hospital from January 2020 to December 2022 were selected to undergo ultrasound elastic imaging examination. The pathological examination results of 85 patients with breast mass were analyzed, elastic imaging parameters of benign and malignant tumors were compared, and ROC curves were drawn for elastic strain rate, diameter change rate, area ratio and the three combined. The elastic imaging parameters of different clinical stages of breast cancer patients and the elastic imaging parameters of pathological molecular classification of breast cancer patients were analyzed. Results: Among 85 patients with breast mass, 35 cases were benign and 50 cases were malignant.The elastic strain rate, mass diameter, diameter change rate, mass area and area ratio in the malignant group were significantly lower than those in the benign group (P<0.05). The area ratio ROC curve AUC was 0.580, with 1.73 as the critical value, the diagnostic sensitivity and specificity of breast malignant tumor were 73.5% and 38.5%. The ROC curve of diameter change rate was 0.630 with 0.28 as the critical value. The diagnostic sensitivity was 75.5% and the specificity was 47.5%. The ROC curve of elastic strain rate was 0.790, with 15.2 cm2 as the critical value, the diagnostic sensitivity was 64.5%, and the specificity was 83.5%. The ROC curve was drawn with the three factors combined, and the AUC was 0.920, the diagnostic sensitivity was 82.5%, and the specificity was 92.5%. There were significant differences in the elastic strain rate, mass diameter, diameter change rate, mass area and area ratio in patients with breast malignant tumor at TNM stage Ⅰ, Ⅱ, Ⅲ and Ⅳ (P<0.05). Among them, the elastic strain rate, mass diameter, diameter change rate, mass area and area ratio of stage Ⅳ were significantly higher than those of stage Ⅲ, Ⅱ and Ⅰ, stage Ⅲ was significantly higher than those of stage Ⅱ and Ⅰ, and stage Ⅱ was significantly higher than those of stage Ⅰ. The differences of elastic strain rate, mass diameter, rate of diameter change, mass area and area ratio in Luminal A, Liminal B, Her2 overexpression and basal-like patients with breast malignant tumor were statistically significant (P<0.05). The elastic strain rate, mass diameter, rate of diameter change, mass area and area ratio of the Liminal B type are significantly higher than those of Luminal A, Her2 overexpression and basal-like type, and the overexpression of Her2 is significantly higher than those of Luminal A and basal-like type (all P<0.05). There was no statistical significance between Luminal A type and basal-like type (P>0.05). Conclusion: Ultrasound elastic imaging can be used for the diagnosis of benign and malignant breast tumors, and the quantitative parameters of ultrasound elastic imaging can be used to judge the clinical stage of malignant breast tumors, the Liminal type B, the Her2 overexpression type. [ABSTRACT FROM AUTHOR]