Abstract: Objective: To evaluate the clinical value of CTA(CT Angiography, CTA) in the diagnosis and treatment of intracranial aneurysms. Methods: 97 cases of patients with clinically suspected of intracranial aneurysms were randomly detected by one of the non-invasive examination CTA and MRA first, and then underwent a DSA examination. Comparing with DSA and surgical diagnosis, we discussed the advantages and disadvantages of CTA, MRA and DSA. After acceptance of the appropriate treatment, patients underwent a CTA + DSA examination or a MRA + DSA examination, and evaluate of residual aneurysm case. Results:(1) 50 patients in CTA + DSA inspection group, 46 cases were confirmed as positive cases. The specificity, sensitivity and accuracy of CTA detection were: 66.67%, 100%, and 98%. Negative and positive predictive values were: 100%, 97.92%. The specificity, sensitivity and accuracy of DSA detection were: 66.67%, 95.74%, and 94%. Negative and positive predictive values were: 50%, 97.83%.(2) 47 patients in MRA + DSA inspection group, 45 cases were confirmed as positive cases. The specificity, sensitivity and accuracy of MRA detection were: 50%, 97.67%, and 93.62%. Negative and positive predictive values were: 66.67%, 95.45%. The specificity, sensitivity and accuracy of DSA detection were: 66.67%, 97.73%, and 95.74%. Negative and positive predictive values were: 66.67%, 97.73%.(3) 48 patients who underwent aneurysm clipping surgery detected by CTA + DSA examination, and DSA as the standard, CTA evaluation of residual aneurysm specificity, sensitivity and accuracy were: 97.73%, 100%, and 97.78%. 42 cases accepted relief coil therapy detected by MRA + DSA examination,and DSA as the standard, MRA evaluation of residual aneurysm specificity, sensitivity and accuracy were: 100%, 66.67%, and 97.5%. Conclusion: CTA diagnosis of intracranial aneurysms specificity, sensitivity and accuracy slightly better than DSA, MRA for the diagnosis of intracranial aneurysms is slightly lower than the DSA; while CTA and MRA can clearly show the three-dimensional structure of the aneurysm and spatial relationships; comprehensive comparison, we believe that CTA for the diagnosis and determine aneurysm surgery programs can provide more information. And CTA can be used as an ideal follow-up after imaging methods.