Abstract： Objective To find the effective quantitative parameters for the differentiation of the breast lesions using the post-processing of time.signal curve of 3D dynamic-enhanced MRI.Methods Thirty patients with 35 lesions underwent 3D dynamic-enhanced MRI and the time-signal cHIve was deduced.The four quantitative parameters including SImax,PH,Slope and SlopeR were analyzed in benign andmalignant lesions of the breast.Independent samples t test and rank sum test were used for the statistics.Results Seyenteen benign lesions and 18 malignant lesions were included in this study.The SImax(M)of benign and malignant lesions were 375.2 and 158.1,the 95% confidence intervals of SImax were 278.2-506.0 and 160.5-374.8.The PH(M)of benign and malignant lesions were 114.4 and 87.8,the 95% confidence intervals of PH were 73.7-196.5 and 71.3-162.9.The Slope(M) of benign and malignant lesions were 22.3×10-3 and 44.0×10-3,the 95% confidence intervals of Slope were 13.7×10-3-41.1×10-3 and 46.1×10-3-81.8×10-3.The Slope"(M) of benign and malignant lesions were 2.6 and11.4,the 95% confidence intervals of SlopeR were 1.9-3.4 and 9.8-14.5.There were no significant differences on SImax and PH between benign and malignant lesions(P>0.05).The significant differences existed on Slope(P<0.01)and SlopeR(P<0.01)between benign and malignant lesions of the breast.Conclusion SlopeR is a very effective parameter in t}le differential diagnosis of breast lesions.