Abstract: Objective To explore the characteristicc and evaluatio n of B-ultrasonography to diagnosis breast occupancy lesions. Methods Detect 40 cases breast occupancy lesions with Germany Performa ultrasound v id eograph instrument,and were contrasted by diagnosis of pathologic histology. Results Among the B-ultrasonography dianosis of 40 cases there had 32 cases were accorded with pathologic diagnosis,and 8 cases were not. Conclusion The sensitivity of breast diagnosis is 85%,and specificity is 6 7%.Non isotrope low echo mass,it has a irregular shape,and rough borderline,an d en hanced front lateral margin is the gist to diagnosis breast carcinoma.