Objective　To investigate the anatomy of anterior sphenoid sinus wall and its significance for the transsphenoidal surgery.　Methods　Fifteen cases (30 sides) of adult cadaveric skulls and 20 cases (40 sides) of bleached adult dry skulls were observed under microscope. The bone structure of anterior sphenoid sinus wall and the sphenopalatine arteries and their branches were measured.　Results　The anterior sphenoid sinus wall resembled a bird head, with midline prismatic protrusion. The sphenoid ostia on both sides were in shape of bird-eyes, and the sphenoidal rostrum below was like the beak.  The sphenoid sinus ostium was (14.5±1.1) mm from the terminal of upper nasal meatus, (12.2±1.0 )mm from the posterior choanae, and (8.2±0.5)mm (6.6~12.2 mm) from the upper branch of nasal septum artery. A straight probe was stretched from the nostril to the anterior sphenoid sinus wall to determine the nearest point on this wall, which was defined as the "shallowest point". This point was at about the middle point between the sphenoid sinus ostium and the posterior choanae. Sphenopalatine foramen was located inferolateral to the sphenoid sinus ostium and at the rear of middle turbinate, with a distance of (6.9±1.3) mm to the sphenoid sinus ostium. The distance between the medial edges of sphenopalatine foramen on both sides was (18.2±2.5) mm.  Conclusions  The anterior sphenoid sinus wall has its own morphological characteristics. The sphenoid sinus ostium was located at the junction of the upper and middle thirds of the anterior sphenoid sinus wall. There is a protuberance bellow the ostium. The sphenopalatine foramen was inferior-lateral to the sphenoid sinus ostium, with about 7 mm from each other. This data should be useful for positioning the sphenopalatine foramen in the transsphenoidal surgery.