To evaluate the therapeutic effect of sterotactic radiosurgery(RS) of intracranial arteriovenous malformations(AVMs) and to observe the detailed changes in and around the lesions after this treatment method, we reviewed and compared the angiographic and CT findings of 6 patients examined before and 6 to 19 months after treatment with this high energy photon beam radiotherapy by linear accelerator through the sterotactic method. Four out of 6 patients(67%) with small AVMs(1.0-2.7cm3) showed significant reduction in volume more definitely on the angiograms(8%-48%) than the CT scan images, but both diagnostic modalities were able demonstrate the efficacy of steretactic radiosurgery in the treatment of intracranial AVMs. Angiograms also to demonstrated delayed blood flow and decreased size of major draning veins in 3 patients and a small focal vascular defect in another patient with minimal volume change which were not detected in CT images. Angiography proved to be a more reliable imaging technique than CT for the follow-up of these lesions.