Objective：To search for a safe approach for transsphenoidal endoscopic pituitary surgery, so as to avoid injury of intercavernous sinuses during the operation. Methods： The anterior intercavernous sinus, posterior intercavernous sinus, inferior intercavernous sinus, basilar sinus, and dorsum sella sinus of 20 Chinese adult cadavers were surgically observed; and the relevant data were obtained and analyzed. Results： The existence rates of anterior intercavernous sinuses, posterior intercavernous sinuses, inferiorintercavernous sinuses, basilar sinuses, dorsum sella sinuses were 95%（19）, 75%（15）, 10%（2）, 100% （20） and 30%（6）,respectively; their anteroposterior diameters were （2.08±0. 90） mm,（5. 14±2. 54） mm,（1.30±0.40） mm,（2.26±1.02） mm, and （2. 01 ± 0. 80） mm, respectively; and their supra-inferior diameters were （2. 74 ± 0. 96） mm, （1.10±0.74） mm, （1.48±0.29） mm, （15.67±4.54） mm, and （3.35±1.93） mm, respectively. The distance between inferior edge of anterior intercavernous sinus and the anterior edge of posterior intercavernous sinus was （5. 78 ± 1. 89） mm. Conclusion：The intercavernous sinus should be avoided to expose the pituitary after opening the antapex of sella trucica during transsphenoidal endoscopic pituitary surgery. When the intercavernous sinus can not be avoided, reasonable incision and hemostatic method should be selected before operation to prevent severe bleeding.