Abstract: Objective To compare the cardiovascular and cerebrovascular complications and clinical characteristics of Cushing's disease patients with different serum potassium levels. Methods Clinical data about 187 adult Cushing's disease patients admitted to our hospital from 1991 to 2011 were retrospectively analyzed.The patients were divided into two groups according to their serum potassium level.Their cardiovascular and cerebrovascular complications and clinical characteristics were compared. Results The average age of the patients was 20-76 years (mean 38.8±11.3 years).Of the 187 patients, 43.3% (81/187) were diagnosed with hypokalemia.The number of males was greater than that of females, the course of disease was shorter, the blood pressure and blood lipid level and the incidence of striae, ecchymoses and edema of lower limbs were higher in patients with hypokalemia than in those with a normal serum potassium level(P＜ 0.01).It was easier to occur alkalosis in patients with hypokalemia than in those with a normal serum potassium level(P＜ 0.05).The serum levels of ACTH, F, and 24 h UFC were significantly higher in patients with hypokalemia than in those with a normal serum potassium level(P＜ 0.01).The negative rate of dexamethasone inhibition test and the incidence of complications and arrhythmia were significantly higher in patients with hypokalemia than in those with a normal serum potassium level(37.1% vs 9.4%, 56.8% vs 41.5%, 35.4% vs 21.9%, P＜ 0.05).No significant difference was found in the incidence of left ventricular hypertrophy, angina pectoris, myocardial infarction, and cerebrovascular events between the patients with a normal serum potassium level and those with hypokalemia (P＞ 0.05). Conclusion Hypokalemia usually occurs in males.Its course is shorter, its signs are more significant, the abnormal metabolism is severer, the hormone level is higher, and the incidence of vascular complications is higher in hypokalemia patients, especially in those with arrhythmia and proteinuria.