To discuss the image anatomy characters in the height and contour of the ethmoid roof.Retrospective review of direct coronal sinus computed tomography (CT) scans in 160 patients. The height and contour of the fovea ethmoidalis, and the connection modes between ethmoidal roof and cribriform plate were examined. When an asymmetry in the height of the fovea ethmoidalis existed, this difference was quantified, and the difference between ethmoidal roof and cribriform plate was quantified in high type, too.In 25 scans (15.63%), there was an asymmetry between the height of the fovea ethmoidalis on the right and left sides. Of these 25, 13 (52.00%) were lower on the right side. The difference between left and right was 2.35 mm. Sixty-two patients (38.75%) demonstrated a contour asymmetry with "flattening" of the ethmoid roof on one side. Horizontal type was 116 sides (36.25%), and high type was 204 sides (63.75%) in the connection modes between ethmoidal roof and cribriform plate. The difference was 2.80 mm in the high type.There were asymmetries in the height and contour of the right and left fovea ethmoidalis. The asymmetry was most often the result of a difference in contour with flattening of the fovea on one side. The high type was the most connection modes between ethmoidal roof and cribriform plate. This underscores the importance of careful preoperative and intraoperative review of paranasal sinus CT scans in patients undergoing endoscopoic sinus surgery.