Objective：To provide anatomic data for accurately localizing aperture of sphenoidal sinus without injurying sphenopalatine arteries in endoscopic transsphenoidal sella surgery. Methods： The anterior walls of spheroid sinus were observed and measured （layout, position, external diameter,distances to other structures of interest） with a vernier caliper and an angle gauge on 15 adult cadavers. Results： The distances from the root of columella nasi to the inforior pole of sphenoidal sinus aperture and the sphenopalatine foramen were （60.40±3.21,58.10-72.76） mm and （62.14±1.93,59.50-73.40） mm, respectively. The distance from the inforior pole sphenoidal sinus aperture to the sphenopalatine foramen was （12.20±1.10,8. 10-16.35） mm. The diameter of the sphenopalatine artery was （1.99 ±0.13,1. 50-2. 80） mm. The distances from the inforior pole of sphenoidal sinus aperture to the superior and inferior posterior artery of nasal septum were （3.49±0. 24,2. 78-5.20） mm and （6.42±1, 08, 4.30-8. 50） mm, respectively . Conclusion： Aperture of sphenoidal sinus is an important marker in endosopic transsphenoidal sella surgery. The anterior wall of sphenoid sinus should be opened from the inforior pole of sphenoidal sinus aperture to avoid injurying sphenopalatine artery.