Abstract: Objective To evaluate the diagnostic value of dense vein sign on non-contrast enhanced CT of cerebral venous sinus thrombosis (CVST) in different sites and states. Methods Neuroimaging data about 49 patients with CVST who all underwent CT, MRI and DSA/MRV/CTV in our hospital from 2006 to 2013 were collected. Results of MRI and DSA/MRV/CTV were employed as the golden standard to determine thrombosis in superior sagittal sinus, transvers and sigmoid sinus, as well as strait sinus. The positive rate of dense vein sign in different periods after onset of symptoms was analyzed. Results Of the 49 patients, thrombosis was detected in 92 major cerebral venous sinus based on MRI+DSA/MRV/CTV, including 31 in superior sagittal sinuses, 25 in left transverse sinuses and sigmoid sinuses, 26 in right transverse sinuses and sigmoid sinuses, 10 in straight sinuses. The positive rate of dense vein sign in the above thrombosed sinuses was 32.3%, 40%, 42.3%, 90% respectively. And the positive rate of dense vein sign was 80.8% within 7 days, 37.0% between 8 and 30 days and 23.1% after 30 days of symptoms onset. Conclusion Dense vein sign on axial non-contrast enhanced CT can identify venous sinus thrombosis and it is a sensitive feature of thrombosis in major cerebral venous sinus within 7 days while it can be found less frequently after 7 days. Identification of the incidence of dense vein sign on non-contrast enhanced CT is a useful tool in the diagnosis of CVST.