Objective To explore the combination of dynamic contrast enhancement and diffusion weighted imaging in the diagno-sis of breast diseases.Methods 67 patients with breast mass proven by operation or biopsy underwent dynamic contrast enhance-ment and diffusion weighted imaging.Fischer scoring system and BI-RADS were used to distinguish the benign lesions from the ma-lignant mass.The optimal boundary value of ROC curve was set as the threshold in DWI.The independent and conj unctive diagnos-tic efficacy of DCE and DWI were calculated and compared.The conj unctive methods included combinated properly method and DCE used as the chief diagnostic method while DWI as the adj unctive method.Results the best diagnostic boundary of ADC values was 1.1×10-3 mm2/s,The sensitivity,specificity and diagnostic accuracy of DWI and DCE were 71.4%,88.6%,80% and 100%, 80%,90%,respectively.The value was 85.7%,94.3%,90%,when using DCE chiefly and DWI adjunctively,while it was 91.4%respectively in combinating properly method.Conclusion DWI can improve the specificity of MRI in diagnosing breast lesions while it can reduce the sensitivity,which can results in the missed diagnosis of malignant diseases.DWI can used as an auxiliary examina-tion method to increase the diagnostic confidence of DCE method.