Objective To investigate the therapeutic effect of intravascular embolization of carotid-cavernous fistulation.Methods 5 cases were examined by DSA of brain to find out the sites of fistulation.The detachable balloon or GDC(Guglielmi Detachable Coil)were employed in embolotherapy.Results 1 cases were embolized successful with detachable balloon and kept free circulation of ICASs;The embolism of ICA involved side were performed in 2 cases for patient with pseudoaneurysm and 1 patients cavernous involved were embolized with GDC for small mouth of the fistula.Another case balloon raptured two times when it was detached to cavernous after one free balloon was dept in cavernous,the patient didn't want to embolized the ICA involved,the trentment was stoped,the patients symptoms was disappeated after one week of therapy.Conclusion The site and size of carotic-cavernous fistulation can be detected by DSA of brain intravascular embolization is the first-choise method of therapy for it.