Objective  To present anatomical landmarks for endoscopic transpterygoid transmaxillary approach to the upper parapharyngeal space.    Methods  Anatomy of the upper parapharyngeal space using endoscopic endonasal transpterygoid transmaxillary approach was performed in cadaveric head. The distances between medial pterygoid plate, lateral pterygoid plate and styloid process were measured, respectively. The distances between lateral pterygoid plate, sphenoid spine and the entrance of carotid canal were also investigated.    Results  The dissection was performed in 10 fresh cadaver heads (20 sides). The distance between medial pterygoid plate, lateral pterygoid plate and styloid process were (28.1±3.3)mm and (18.9±4.9)mm respectively. The distances between lateral pterygoid plate, sphenoid spine and the entrance of carotid canal were (14.1±3.7)mm and (6.7±1.5)mm respectively. Pharyngobasilar fascia，medial pterygoid muscle and tensor veli palatini muscle were key landmarks of the upper parapharyngeal space.   Conclusion  The bone landmarks of lateral pterygoid plate and sphenoid spine are effective in identification of the entrance of carotid canal, which is helpful to locate the parapharyngeal segment of internal carotid artery.