Abstract： Objective To recognize the normal CT appearances of adult pterygoid hamulus and increase the ability to recognize pterygoid hamulus abnormalities.Methods The pterygoid hamulus of 108 normal adults ( male:53 cases,female,55 cases) were studied with MIP and VR reconstructive images by 64-slice spiral CT in order to observe its normal shape,to measure its length,diameter,vertical height,horizontal width,abduct angle in coronal position and post-abducent angle in anteroposterior position.The differences between genders,two sides and age groups were compared,respectively.Results The normal pterygoid hamulus had a wide basal body and a pillar caudomedial part with round or intumescentia extreme.In coronal position,the distal end towards outer direction in 214 sides and 2 sides in inner direction. In anteroposterior position,the distal end towards posterior direction in 190 sides and anterior direction in 26 sides.The pterygoid hamulus length,vertical height,and horizontal width of adult males were (8.18 ± 0.94) mm,(7.23 ±0.92) mm,(4.27 ±0.81 ) mm,respectively.They were larger than the adult females (7.31 ± 1.01) mm,(6.26 ±0.90) mm,(3.97 ±0.82) mm,and the difference was statistically significant (t values were 6.56,7.86,2.72 respectively,P ＜ 0.05).The pterygoid hamulus vertical height of age group over 60 years old (7.13 ± 1.35) mm exceeded the age groups of 18-39 (6.55 ±0.86) mm.The difference was statistically significant ( F =4.95,P ＜ 0.05 ).Conclusions 64-slice spiral CT could display the shape,length and angle of pterygoid hamulus in full. It could help to recognize correlated pterygoid hamulus diseases.