A potential role in the differentiation of molecular subtypes and to facilitate lesion-specific targeted therapies.To evaluate the breast characteristics of invasive cancers on dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) assessed as parameters in comparison with different molecular subtypes.This retrospective study was approved by the institutional review board. A total of 164 lesions in 161 women who underwent preoperative breast imaging of both DCE-MRI and DWI((A 3.0T system GE-Signa HDXT)) were reviewed. According to the receptor status, tumor subtype was categorized as Basal-like, luminal A, luminal B, and Herb 2+. The following lesion characteristics were recorded: DCE morphology and maximum lesion size, initial phase peak enhancement, delayed phase enhancement categorized by a single type of kinetics comprising the largest percentage of enhancement (washout, plateau, or persistent) with CAD analysis, apparent diffusion coefficient (ADC) values, and contrast-to-noise ratio (CNR) at DWI with b values from 0 and 800 s/mm². All the above work operated by two radiologists by using the GEAW4.5 workstation. And then the SPSS17.0 statistical software was used for the data analysis. Kruskal-Wallis rank sum test was performed in MRI characteristics of the four subtypes. Discriminative abilities of models were compared by using the area under the receiver operating characteristic curve (AUC). For the tumor subtypes of 164 invasive breast cancers, 34 (20.7 %) were Basal-like, 69 (42.1 %) were Luminal A, 40(24.4 %) were Luminal B and 21 (12.8 %) were Herb2+.Compared with other three subtypes, Basal-like lesions exhibited, larger maximum lesion size, while no difference in lesion type among four subtypes, more details referent to Figure.1. There were significant differences of lesion margin, internal enhancement features of mass, delayed phase of enhancement and CNR (b=800s/mm²) values were observed among four subtypes (p<0.001, p<0.005, p=0.002, and p<0.001), while lesion shape, initial phase peak enhancement parameters, mean ADC value or CNR (b=0) values were not (p=0.789, p=0.07, p=0.099, and p=0.35), concrete values are listed in Figure.2. A multivariate model combining maximum diameter, mass margin, CNR with b values of 800 s/mm² and delayed phase enhancement most significantly discriminated Basal-like from other three subtypes (Figure.3 AUC=0.84). Breast cancer is the most common cancers for female in China from a report of cancer incidence and mortality in China (2010)^[1].The most common molecular classification of Invasive cancer is Basal-like, Luminal A/B and HER2+. In our study, DCE and DWI were used simultaneously. DCE MRI findings in our report showed Basal-like with more circumscribed margin (72.4%), rim enhancement (69%) than other three subtypes. Regarding enhancement kinetics, delayed phase of enhancement of CAD analysis was more helpful in differentiating four subtypes, 62.1 % of Basal-like showed a washout enhancement pattern in our study, while the percent was slower than the present study in the literature (95%)^[2-3]. DWI can yield novel quantitative and qualitative information reflecting cellular changes that can provide unique insights into tumor cellularity^[4]. To our knowledge, this is the first study of CNR characteristics of different molecular subtypes of breast cancer. While there was no significant difference among four subtypes in the assessment mean ADC value. In our study, a multivariate model combining maximum diameter, mass margin, higher CNR with b values of 800 s/mm2 and delayed phase enhancement could be useful in differentiating Basal-like from luminal A, luminal B, and Herb 2+.In addition to the morphological features, DCE-MRI and DWI could provide novel quantitative information reflecting invasive cancers microenvironment changes, with a potential role in the differentiation of molecular subtypes and to facilitate lesion-specific targeted therapies.