Abstract： Objective To study the morphological characteristics of pituitary glands in healthy adult of the Han nationality on the High-resolution MRI and provide morphological data of pituitary glands for the construction of database for Chinese Standard Brain.Methods This is a clinical multi-center study.Nine hundred and seventy eight Chinese healthy volunteers (age range = 18 to 70) recruited from 16 hospitals were divided into 5 groups, i.e., Group A ( age range = 18 to 30), B ( age range = 31 to 40), C ( age range = 41 to 50), D ( age range = 51 to 60 ), and E ( age range = 61 to 70).All of the volunteers were scanned by MR using T, weighted three-dimensional magnetization prepared rapid acquisition gradient echo sequence.By Multiplan reconstruction with 3D software, the pituitary gland's volume, size, and inclination of pituitary stalk were measured and the differences between sexualities and among age groups were compared by analysis of variance using SPSS13.0; those among five age groups were compared pair-wised by Tukey analysis; and the differences between male and female were analyzed by independent t test, and the differences of measurements of typing of pituitary glands were analyzed by Chi-square analysis.Results( 1 ) Volume of pituitary glands: the mean volume of male and female among 5 age groups were ( 1142±290), (996±223), (979 ±178), (971 ±174), (930 ±189) and (1247 ±210), (1199 ±216),( 1108 ± 196), ( 1059 ± 212 ), (984 ± 177 ) mm3 respectively.There were significant differences among the age groups(F = 13.811,27.091 ,P <0.01), the volume tended to decrease after 30 years old in male and 40 years old in female.Female has bigger volume than man in the same age group (P < 0.05).There were statistically correlation between sexes, age, typing, heights in middle sagittal width in coronal MR and anteroposterior diameter in middle sagittal MR.(2) The size of pituitary giands:the mean heights on middle sagittal MR images of male and female among 5 age groups were(6.6±1.5), (6.0±1.4), (5.6±1.1 ),(5.0±1.2), (4.9±1.4)and (7.9±1.6), (6.4±2.0), (5.6±1.7), (5.1±1.7), (4.4±1.4)mm respectively.There were significant difference among the age groups ( F = 24.582,62.978, P < 0.01 ).Females demonstrated larger pituitary glands than men in the age from 18 to 30 year old groups ( P < 0.01 ).The pituitary height tended to decline after 30 years old, minimum after 50 years old group in male and 40 years old in female.The heights were statistically correlated with sexes and age.The mean width in coronal MR images of male and female among 5 age groups were( 14.8± 1.8), ( 14.7 ± 1.4), ( 14.2±1.9), (14.3 ±2.1), (13.8 ±2.4) and (14.9±1.8), (15.8±1.7), (15.5±2.1), (15.6±2.2),( 14.9±2.1 ) mm respectively.There were significant difference among the age groups( F = 4.566,4.233,P<0.05),The width of pituitary before 30 years old and after 60 years old were smaller than the other groups (P <0.05 ), but man did not show this relationship.The widths were statistically correlation with sexes, age and weight.The mean anteroposterior diameter in middle sagittal images of male and female among 5 age groups were (11.2±1.2), (11.8±1.3), (11.8±1.5), (12.3±1.8), (12.2±2.0) and (11.9±1.3), (12.5±1.5), (12.4±1.5), (12.9±1.6), (12.7±1.6)mm respectively.There were significant difference among the age groups ( F = 7.270, 5.903, P < 0.01 ).Before 60 year old, the anteroposterior diameter was smaller in male than all female groups (P < 0.05 ), and there was a tendency to grow downwards with age.The anteroposterior diameter was statistically correlated with sexes and age.(3)The angle of inclination of pituitary stalks: on reconstructed coronal MRI imaging, the angle of inclination of pituitary stalk were in the middle, no significant differences in the angle measurements were found between male and female among 5 age groups ( P > 0.05).(4) The typing of pituitary glands in middle sagittal MR images : there were significant differences between each typing ( χ2 = 44.212, 107.518, P < 0.01 ), there was a tendency of pituitary upper border to depressed when age increased.Conclusions With highresolution MRI and 3D volumetric analytic software, volume and size of pituitary glands and the angle of inclination of pituitary stalks were accurately measured, and that provide morphological data of pituitary glands for the construction of database for Chinese Standard Brain.