As histological benign tumor with malignant cellular characteristic, craniophayrngyioma (CP) caused big trouble not only for surgery but also for the postsurgical management. So, it is important to emphase the understanding of the pituitary gland and also it’s connected structures, such as pituitary stalk, hypothalamus, and so on. In this chapter, we described the anatomical and cytological constructors of pituitary gland. As with combined the etiology of CP, we depicted the embryonic development of gland and its accessory structures. On the other hand, several hypotheses about the origin of CP were also analysed and described.