Objective To explore the clinical features and evaluate the diagnostic methods for adrenal tumors and bilateral adrenal hyperplasia (BAH) before surgical operation.Methods Clinical data of 45 cases with adrenal tumor and BAH were analyzed.Results Of 45 cases,15 were with aldosterone producing adenoma (APA),3 with of BAH,8 pheochromocytoma,4 adrenal tumor with hypercortisolism and 15 adrenal incidentaloma.Conclusions Before operation,endocrine function examinations of adrenal tumors are necessary for preventing preoperational complications.