Objective　To evaluate the effect of intravascular occlusion for carotid cavernous fistula (CCF) by analying the clinical features of CCF. Methods　Twelve cases with CCF were analysed on their medical histories, clinical features in the eyes, clinical examinations and the therapeutic effects of balloon occlusion in internal carotid artery.Results　Ten cases were treated successfully(83.33%), in which 2 cases were treated once more. There was no operation complication. The visual acuity of one case increased from no light perception to finger movement within 1 week preoperatively. The visual acuity of 10 cases improved 1～4 lines (Snellen chart). Some clinical symptoms and signs such as the lid, conjunctiva swelling, diplopia, the movement of eyeball and retinal hemorrhage were decreased remarkably. Carotid fistula of 12 cases with CCF were found to be occlusioned by digital subtraction angiography after operations.Conclusion　The early diagnosis and treatment for CCF are necessary. Color doppler flow imaging, CT and DSA are useful examination methods for diagnosis of CCF. Intravascular occlusion is the best therapeutic method for CCF nowadays.