Abstract: Objective To investigate the correlations among MRI morphologic feature, the early-phase enhancement rate, apparent diffusion coefficient (ADC) and HER-2 of breast cancer. Methods Sixtythree patients diagnosed as breast cancers by pathologic examination were reviewed, including MRI features and the expression of HER-2. The morphologic features were observed in early phase. The early-phase enhancement rate and the value of ADC were also calculated. All statistical analyses were performed by using SPSS11.5. Results In the cases with breast cancer, the high expression rate of HER-2 had correlation with necrosis, with higher overexpression rate in patients with necrosis than in the others(χ2＝4.257，P＝0.039). The high expression rate of HER-2 had no correlation with the margin(χ2＝0.100，P＝0.921). The expression rate of HER-2 had no correlation with the early-phase enhancement rate(r＝0.159，P＝0.215). The value of ADC had negative correlation with the expression rate of HER-2(r＝-0.366，P＝0.003). Conclusion MRI features can refl ect the expression of HER-2 in breast cancer partly.