Objective: To observe the application of CR system in molybdenum mammography and investigate the accuracy of CR system in diagnosing breast diseases.Methods: 45 cases were study by IP plate, MIEV molybdenum. Taking galactophore X-ray with Axial and Oblique positions firstly, then having laser films taken by the post-processor of CR system.Results: Of the 45 case,20 cases were diagnosed bengin diseases,and 25 cases were malignant tumor,the accuracy of CR system was 90% as compared with postoperative pathologic diagnosis.Conclusion: CR technology plays an outstanding role in aspects of diagnosis, differentiating diagnosis, discovering tumour in early stage.