Gigantism is a rare condition that causes abnormal growth in children. It occurs when a child’s body produces too much growth hormone. Early diagnosis is important. Prompt treatment can stop or slow the changes that may cause a child to grow larger than normal. However, the condition can be hard for parents to detect, since symptoms of gigantism might first be seen as normal childhood growth spurts. The clinical characteristic of giant’s disease is caused by GH and its target hormone IGF-1. GH secretion is regulated by the hypothalamic hormone, GH releasing hormone (GHRH) stimulates the secretion of GH, while SS inhibits the secretion of. The basic morphological changes of pituitary in GH patients are increased by the number of GH cells, the most common pathological changes are clear, but the GH cells are not encapsulated in the capsule. The number and distribution of GH secreting cells in the pituitary gland are normal. GH cells caused by the increase in the number of lesions can be located in the hypothalamus, pituitary, and even the skull, leading to the giant’s most of the pituitary tumor. In addition,hypothalamic GHRH tumor and ectopic GHRH tumor not only can cause GH cell hyperplasia, but also can cause GH tumor. Therefore, GHRH is one of the causes of pituitary tumors. In vitro experiments showed that GHRH stimulated the growth of GH cells, suggesting that GHRH receptors were present in these tumor cells. There is no proliferation of GH in the tumor, which does not support the theory of pituitary tumor formation, but it may be due to the effect of GH on the proliferation of GHRH cells by short loop negative feedback. It has been demonstrated that the GHRH can cause tumor formation in transgenic mice. But in sporadic GH tumors, excessive GHRH causes the rare pituitary adenoma and hyperplasia of GH cells. GH overexpression and GH tumor cause people grow too taller than others, Acromegaly, Skin and soft tissue, sugar metabolism, cardiovascular system, respiratory system and so on. Treatment ways are Radiation therapy, surgical treatment, Medication.