Aim To investigate the preliminary scanning significance of artery stenosis with intracranial internal carotid artery’s plaque calcium score using conventional brain unenhanced computed tomography （CT）. Methods By retrospectively analyzing brain and neck CT artery imaging （including conventional brain unenhanced CT, CTA） of 110 cases, the intracranial internal carotid artery’s calcification were classified into 4 grades. Of them, there are 26 cases which can be successfully classified into 3/4 grade by Agatston Calcium Score and receive CT artery imaging analysis of vascular and artery （AVA） software. AVA software was used to analyse the calcification segment artery’s stenosis degree and its North American Symptomatic Carotid Endarterectomy Trial criteria （NASCET） classification. Results In the 26 cases, there are 18 cases of mild grade with Agatston Calcium Score 2.69±1.01, 5 cases of moderate grade with Agatston Calcium Score 5.25±0.88, 3 cases of high grade with Agatston Calcium Score 6.80±0.30. The difference between high, moderate grade and mild grade has statistic significance （P<0.05）. The difference between high and moderate grade has no statistic significance （P>0.05）. There were positively significant correlation between stenosis degree and calcification’s Agatston Calcium Score（r0.938，P<0.05）. Conclusions Conventional brain unenhanced CT intracranial internal carotid artery’s Plaque Calcium Score can be used to scan artery stenosis, and the one with Agatston Calcium Score over 5.25±0.88 is suggested to proceed CTA examination.