Abstract： Objective To determine the value of acoustic radiation force impulse elastography (ARFI) combined with conventional ultrasound in identifying the nature of breast masses.Methods A total of 102 female patients who visited our hospital between January 2013 and January 2014 for ultrasonography of breast masses were included in the study.According to tumor size,the patients were divided into 3 groups (＞20 mm,10-20 mm,and ＜10 mm),and all of them underwent two-dimensional ultrasonography,color Doppler ultrasonography and ARFI.We analyzed the diagnostic specificity and sensitivity for breast diseases between conventional ultrasonography alone and combined with ARFI.The differences in shear wave velocity (SWV) of benign and malignant tumors were compared within and between groups.Results ARFI combined with conventional ultrasonography yielded a sensitivity of 95.2％ and a specificity of 98.8％,compared with a sensitivity of 81.0％ and a specificity of 92.6％ by conventional ultrasonography alone,with statistical significant differences (all P＜0.05).The SWV for malignant tumors [(5.61 ± 0.16) m/s (＞20 mm),(3.35 ± 0.24) m/s (10-20 mm),(2.42±0.11) m/s (＜10 mm) was significantly greater than that for benign tumors [(3.00±0.12) m/s (＞20 mm),(2.11±0.06) m/s (10-20 mm),(2.03±0.10) m/s (＜10 mm)] (all P＜0.05).Compared with tumor size ＞20 mm,either malignant or benign tumors with a size ＜10 mm or 10-20 mm was with significantly lower SWV (all P＜0.05).Conclusion ARFI combined with conventional ultrasonography can remarkably improve the diagnostic sensitivity and specificity for benign and malignant breast masses.