Abstract： Objective To investigate the value of dynamic contrast?enhanced MRI (DCE?MRI) in the differential diagnosis of glioblastoma and brain metastases. Methods Twenty patients with high grade gliomas and 20 cases patients with brain metastases proved by surgery and pathology were collected, and patients were examined with conventional MRI and DCE?MRI preoperatively. The ROIs were manually placed in solid parts of the tumors and their surrounding tissues to calculate Ktrans, Kep and Ve values. The Ktrans, Kep and Ve values differences for the solid part and surrounding tissues of the two brain tumors were compared by two independent sample t test. The correlation between Ktrans of the solid parts of the two brain tumors and Ktrans, Kep and Ve values of their surrounding tissues were studied by Pearson correlation analysis. Results The Ktrans, Kep and Ve values of glioblastoma were(0.258 ± 0.063)min-1,(0.398 ± 0.082)min-1, 0.632±0.084, the Ktrans, Kep and Ve values of brain metastases were(0.233±0.053)min-1,(0.357±0.042)min-1, 0.672±0.113. There were no significant differences between the glioblastoma and brain metastases for Ktrans, Kep and Ve values(t=-1.354,-1.982, 1.276, all P>0.05). The Ktrans, Kep and Ve values of surrounding tissues of glioblastoma were(0.093±0.032)min-1,(0.411±0.089)min-1, 0.107±0.021, the Ktrans, Kep and Ve values of&nbsp;surrounding tissues of brain metastases were(0.033±0.010)min-1,(0.204±0.045)min-1, 0.069±0.017. The Ktrans, Kep and Ve values of surrounding tissues between glioblastoma and brain metastases had significant difference (t=-7.978,-9.303,-6.203, all P<0.05). The Ktrans of glioblastoma were correlated with Ktrans, Kep and Ve values of their surrounding tissues (r=0.759, 0.464, 0.651, all P<0.05); The Ktrans values of brain metastases had no relationship with Ktrans, Kep and Ve values of their surrounding tissues (P>0.05). Conclusion The DCE?MRI can quantitatively display the microvascular permeability and accurately evaluate the damage of blood?brain barrier of glioblastoma and brain metastases, which has an important value in studying biological characteristics and differential diagnosis of the two brain tumors.