Laparoscopic resection is a standard treatment for adrenal tumors. Retroperitoneal laparoscopic adrenalectomy (RLA) has an easier and more direct access to the adrenal gland, which is better than the peritoneal approach. A number of studies show that the difficulty of RLA is related to many factors, such as tumor size, gender, body mass index (BMI), distance between costal ridges of renal position (distance between the lower edge of the twelfth rib and the anterior superior iliac spine), the positional relationship of adrenal tumor and the upper pole of kidney, degree of perirenal adhesion and tumor pathological type. All of these factors can influence the operation difficulty. In addition, the experience and skill of the surgeon also greatly affect the surgical process.