The pterygopalatine fossa is a small triangular space which lies in the interval between the posterior wall of maxillary antrum anteriorly and the front of the pterygoid process of the sphenoid bone posteriorly. Although the fossa is deep in the skull, it is easily reached across the air space of the maxillary sinus. The surgery in the pterygopalatine fossa is now safe and feasible for a variety of condition such as epistaxis, vasomotor rhinitis, allergic rhinitis and sphenoplatine neuralgia, which are not controlled by conservative mangements. In each of this condition, the surgeon should know the anatomy of the pterygopalatine fossa including osteology, angiology and neurology. Using 30 sides of Korean adult cadaver skull, the author measured the osteologic relationship in the pterygopalatine fossa including vidian canal, foramen rotundum, greater palatine foramen and pterygomaxillary fissure. And the following results were obtained : 1) Depth of maxillary antrum and location of the orifice of vidian canal ; average A-P length from infraorbital foramen to the posterior wall of maxillary antrum was 36±3.5 mm(29-41 mm), average A-P length from the posterior wall of maxillary antrum to the orifice of vidian canal was 11±3.0 mm(6-18 mm), average A-P length from infraorbital foramen to the orifice of vidian canal was 47±1.8 mm(44-50 mm), average height of the orifice of vidian canal from the floor of maxillary antrum was 29±2.2 mm(25-32 mm), average length from the greater palatine foramen to the orifice of vidian canal was 30±4.7 mm(22-38 mm). 2) Diameter and distance of the orifice of vidian canal and foramen rotundum ; average dimension of the largest diameter of the orifice of vidian canal was 5±1.0 mm(3-7 mm), Average dimension of the shortest diameter of the orifice of vidian canal was 3±0.8 mm(2-5 mm), average dimension of the largest diameter of the orifice of foramen rotundum was 6±1.1 mm(4-8 mm), average dimension of the shortest diameter of the orifice of foramen rotundum was 4±0.8 mm(2-5 mm), average distance between the orifice of vidian canal and foramen rotundum was 7±2.1 mm(3-13 mm). 3) Shape of vidian canal in sphenoid sinus ; flat type was 18 cases (60%), bulging type was 9 cases (30%) and dehiscent type 3 cases (10%). 4) Average length of pterygomaxillary fissure was 16±2.8 mm (16-21 mm).