Objective To discuss the diagnostic value of three-dimensional dynamic contrast-enhanced MR angiography (3D-CE-MRA) in the detection for carotid cavemous fistula (CCF). Methods To retrospectively analyzed 10 cases of CCF which were finally confirmed by DSA or clinical manifestations to compare with the display effect of 3D-TOF-MRA and 3D-CE-MRA in CCF. All of the patients were performed 3D-TOF-MRA and 3D-CE-MRA scan.7 cases of them were caused by trauma, and other 3 cases were Spontaneity. 6 cases were males and 4 cases were females. Results Ten patients of CCF, there were 6 cases found enlarged cavernous sinus, 9 cases found enlarged superior ophthalmic vein, 2 cases found drainage of superior petrosal sinuses and 2 cases of inferior petrosal sinuses, 2 cases found enlarged of cavernous sinus and 2 cases displayed fistula in 3D-CE-MRA, there were 10 cases found enlarged cavernous sinus, 10 cases found enlarged superior ophthalmic vein, 5 cases found drainage of superior petrosal sinuses,7 cases found drainage of inferior petrosal sinuses, 3 cases found enlarged of cavernous sinus and 6 cases displayed fistula in CE-MRA. Conclusion In diagnosis of CCF，3D-CE-MRA is more clear than 3D-TOF-MRA in display enlarged cavernous sinus, venous return and fistula, but when the both cavernous expand at the same time, we need combining with clinical history and other signs to differentiate diagnosis.