Objective:To investigate the diagnostic value of the combination of conventional ultrasound (US) and contrast－enhanced ultrasound (CEUS) in breast lesions of BI－RADS 3-5 grade. Methods:Ninety－nine breast lesions were evaluated by using conventional US and CEUS. The pattern of contrast enhancement and the indexes of time－intensity curve were used to describe the lesions,which was also compared with pathological results. All lesions were classified by BI－RADS method and the malignant lesions ranked higher than BI－RADS 4B. Results:Sensitivity,specificity of US in the diagnosis of malignant breast lesions were: 100%,55.17%,respectively. While the combination of US and CEUS showed a sensitivity of 97.56 %,a specificity of 91.23%. Most malignant lesions displayed growing sizes,more vascularity and bending vascular shape after contrast. The difference value of Peak,TTP, and AUC showed a significant difference between benign lesion and normal tissue. Conclusion:Compared with conventional US,CEUS combined with conventional US may be more helpful for the BI－RADS classification of breast lesions.