Pituitary adenomas secreting adrenocorticotropin hormone（ACTH），known as ACTH-secreting pituitary adenomas，cause hypercortisolism by overproducting ACTH and stimulating bilateral adrenal cortical hyperplasia，a condition also known as Cushing’s disease（CD），which is the most common cause of endogenous hypercortisolism. ACTH-secreting pituitary adenomas lead to a series of severe clinical syndromes，including electrolyte disturbances and disorders of glucose and lipid metabolism，affecting multiple organs and systems throughout the body. Transsphenoidal neuroendoscopic surgery is the first -line treatment for ACTH-secreting pituitary adenomas，with a high remission rate，but postoperative recurrence and persistent disease remain unsolved in the treatment of ACTH-secreting pituitary adenomas. The pathological evaluation of ACTH-secreting pituitary adenomas has important value in determining the nature of the lesions，predicting the prognosis，and selecting the drug therapy. This article reviews the advances in the pathologic evaluation of ACTH-secreting pituitary adenomas，including new immunohistochemical markers and microscopic special features.