The anterior and posterior pituitary lobes of newborns are high signal on T1WI at birth, and most of the anterior pituitary lobes begin to show reduced signal after 6 weeks. At around 2 years of age, the pituitary gland and the brainstem show equal signals. In childhood, the superior pituitary margin is mostly flat, and there is no significant difference between males and females. The pituitary height diameter was (3.9±0.3) mm at 3-5 years of age and (4.2±0.5) mm at 5-10 years of age, showing a good positive linear increase in pituitary height with age in the 3-10 years age group (r=0.73, p<0.001). In the group younger than 12 years, no pituitary height exceeded 6 mm, and no statistically significant differences in pituitary size and morphology existed between the sexes. It is generally believed that pituitary height should not exceed 7 mm during this period, and if pituitary height reaches more than 8 mm, the diagnosis of pituitary microadenoma and pituitary enlargement should be considered, and pituitary enlargement in childhood mostly occurs with precocious puberty. In obese children, the pituitary height and diameter are slightly higher than the normal average, and the proportion of pituitary hyperplasia and pituitary microadenoma is significantly higher than that of the normal population. The normal pituitary MR morphological characteristics in adolescence are obvious hypertrophy of the pituitary gland in adolescence, especially the increase of the high diameter and the upper edge of the pituitary gland, which is more obvious in females. There were significant differences in pituitary height and diameter between men and women. The pituitary height in adolescent females could reach 7-10 mm, but none of the cases exceeded 10 mm, and in males it was significantly larger in adolescence than in childhood or early adulthood, but none of the cases exceeded 7 mm, and in about 20 years of age, the pituitary was significantly larger in females than in males (P=0.004). The anterior pituitary lobe showed sudden growth during prepubertal-adolescent period, especially obvious in females, and there was a significant difference in pituitary height and diameter between males and females, whereas the posterior pituitary lobe did not show sudden growth during this period, and the mean value of posterior pituitary volume was smaller in females than in males during this period. In contrast, in females, there were significant morphological changes. 53% of the females in the 11-20 year old group had superiorly convex superior margins and 25% were nearly round or spherical in sagittal cross-section, so it is assumed that the round or spherical pituitary gland is a functional expression in female puberty. The pituitary gland is significantly more convex in adolescent females than in males and other age groups of females, and a spherical pituitary gland is normal in adolescent females. The spherical pituitary gland is rarely seen in males or other age groups in females and should be further examined if present.