Objectvie To evaluate the histopathological accuracy and clinical value of three-dimensional localizing aspiration biopsy by X-guide in diagnosing unpalpated breast diseases. Methods Manifestations of breast X-ray displayed abnormal in 81 patients and palpating were negative. X-ray manifestations of breast diseases and the locations were observed then three-dimensional localizing puncture by X-guide were done. According to the histopathology, the succeeding, positive, pathological types were accounted. The relation of number of tissue piece captured with pathological positive rate were analysed. The pathological results of aspiration biopsy were collated with finally pathological results (surgery and countercheck). Results Eighty-four focuses were detected in 81 patients by X-ray including 61 micro-calcific focuses, 16 glandulose incrassation, 7 glandulose distorting. Fourty-seven focuses located in outer-up quadrants. Operations were succeeding in all patients,The succeeding rate of puncture was 100%. Positive rate of aspiration biopsy accounted for 79.76%(67/84) including breast carcinoma accounted for 0.75%(6/84), benign disease was 71.42%(60/81), negative rate was 20%(17/84).In 22 operated cases, aspiration biopsy pathological results in 6 breast carcinomas was according to pathological results of surgery. Surgerical operation were performed in 14 cases of 58 benign focuses that both pathological results were consistent. Surgerical operation were performed in 2 cases of 17 negative that pathological results were breast hyperplasia with cyst. X2 test were done between cases of histopathological types from aspiration biopsy and ones from operation that had not statistical significance (X2 =3.2,p=0.74＞0.05).X-rays were performed again in the rest patiens of benign focuses and negative by puncture after more 6 months which manifestations of X-rays had no changed. Conclusion Threedimensional localizing aspiration biopsy by X-guide could correctly localized, positive rate was high and negative rate was low to breast diseases which palpating were negative. It was a valuable means for qualitation of breast disease, specially breast carcinaoma with unconspicuous symptom.