目的　用改进火棉胶包埋技术，为新型的经蝶颅区脑桥腹侧面手术入路提供应用解剖学依据。  方法　采用福尔马林固定成人头部标本30例，取其前颅底。标本经脱钙、脱水等系列处理，分别行三维连续薄切片（厚度0.25 mm）。同时对10例成人脱钙头部标本、100侧干燥头骨标本和临床行颅脑部MRI检查患者50例进行观察和分型统计。  结果　蝶窦形态多样，除有矩形外，还有蚕豆形、鞍形、楔形、椭圆形及“人”字形等。根据视神经管突入程度可分为无隆凸、丘状隆起、半管型凸入和全管型凸入4型。 蝶窦前后径为（10.7±5.8）mm（左），（14.0±4.9）mm（右）。MRI正中矢状面蝶窦后壁Ⅰ型（后壁为一层膜样结构或薄骨板）占64%；蝶窦后壁Ⅱ型（后壁为斜坡的一部分）占36%。  结论　设计新型手术入路采用鼻内窥镜从中鼻道进入，经自然腔道入蝶窦，垂直穿过蝶窦后壁行基底动脉止血和脑桥相关手术；同时为开展新型手术入路提供可靠的解剖学依据。

Objective　To provide the evidence of applied anatomy for creating a new operative route about ventral of pons through sphenoid-skull area with improved celloidin embedding technique.　Methods  Firstly，we obtained the anterior skull bases from 30 adult head specimens fixed by Faure Marin. Then, we made three-dimensional continued thin sections of 0.25 mm after series of processes including decalcification and dehydration. Besides, we observed and measured 10 decalcification heads of adult cadaver，100 sides dry bone skull specimens and 50 specimens of MRI.　Results　The sphenoid sinuses were various in morphology and could be wedge-like, elliptical, rectangular, broad-bean-shaped, saddle-shaped and “λ” -shaped. The sphenoid sinuses could be divided into 4 types according to the bulged optic canal, including no-bulge-type, hill-like-bulge-type, half-canal-bulge-type and whole-canal-bulge-type. The distance from anterior to posterior wall of sphenoid sinus was（10.7±5.8）mm on the left, and（14.0±4.9）mm on the right. The MRI median sagittal plane of posterior wall of the sphenoid sinus type Ⅰ(posterior wall of a membrane like structure or thin bone plate) accounted for 64%; posterior wall of sphenoid sinus type Ⅱ (posterior wall as a part of the slope) accounted for 36%.　Conclusion　With the new approach of the operation, the nasal endoscope can go into sphenoid sinuses through the middle nasal meatus. Then it can pass through the posterior walls of sphenoid sinus vertically and have an operation on ventral of pons. Our outcome will supply reliable anatomical evidence for the new route.