Objective To explore the value of spiral CT in venous phase in measuring the diameter of bilateral transverse sinus.Methods The CT vascular imaging findings of 200 cases at torcular herophili area in our hospital were analyzed retrospectively.The resource images, volume rendering (VR) and maximum intensity projection (MIP) were performed to observe the presentation of vascular anatomy in the torcular herophili area, and to determine the dominant transverse sinus and types of torcular herophili (typeⅠ-Ⅵ).The diameters of bilateral transverse sinus were measured by original CT images.Two groups were categorized according to the genders, and four ones (20-30 years, 30-40 years, 40-50 years and 50-60 years) according to the age.Results Between different genders, there was significant difference in right transverse diameter (P<0.05), and there was no significant difference in left transverse diameter (P>0.05).There was no significant difference among four age groups in bilateral transverse diameter (P>0.05).Conclusion Spiral CT is helpful for the evaluation of the diameter of bilateral transverse sinus.These findings can provide anatomical basis for clinical disease with significant implication.