Objective To assess the usefulness of magnification mamography in breast tumor. Methods Both of the mammographic phantom and the breast of 30 cases with breast mass were underwent the magification mammography and the general mammography , to contrast study the shape, margin, calcification , strand of mass in two methods. Results The accuracy rate of diagnosis in 30 cases with benigh and malignant tumor underwent the magnification mammography was 90% , which was greater than that underwent the general mammography. Conclusion The magnification mammography can help to early detect the breast tumor and improve the rate of checkout and dianosis accuracy.