Abstract: Objective: To evaluate the value of full-field digital mammography( FFDM) and preoperative localization in the diagosis of nonpalpable breast lesions( NPBL). Methods: NPBL in 147 patients were located by FFDM,and confirmed by postoperative pathological results. Results: One hundred and fifty-one lesions were found in 147 patients,149 and 2 lesions were successfully located at first time and the second,respectively. The satisfaction rate was 98. 6%. One hundreed and forty-six lesions were successfully resected. Breast carcinoma in 40 lesions and benign tumor in 111 lesions were found. The accuracy,sensitivity,specificity,positive predictive value and negative predictive value of NPBL in FFDM and location were 72. 2%,90. 0%,65. 8%,48. 6% and 94. 8%,respectively. The differences of shape,distribution and border of calcification and shape,border and density of nodules in the diagnosis of benign and malignant tumor had statistical significance( P 0. 05 to P 0. 01). Conclusions: The NPBL localization guided by FFDM is accurate,less trauma and simple,which can guide the clinic.