Objective：To investigate changes and factors affecting serum parathyroid hormone（PTH） level in patients with primary aldosteronism（PA）and its correlation with parameters of left ventricular structure. Methods：A total of 148 patients with primary hypertension（PH）and 59 patients with PA were enrolled in this study. The plasma levels of aldosterone，renin activity，PTH and calcium and related markers were measured. Parameters of Doppler echocardiography were recorded. Univariate and logistic analysis were conducted to investigate the predicators of serum PTH level. Correlation analysis was conducted between the serum PTH levels and parameters of left ventricular structure. Results：Serum PTH level was significantly elevated，along with decreased calcium levels in patients with PA compared with patients with PH（P < 0.05）. Stepwise multiple regression analysis showed that plasma levels of renin activity（B=-9.229，P=0.030），serum levels of K+（B=-4.577，P=0.003）and Ca2+（B=-11.313，P=0.008） were independently associated with serum PTH level. Serum PTH level was positively correlated with left ventricular diastolic diameter（LVDD），left ventricular end systolic dimension（LVSD）and left atrial diameter（LAD），irrelevant with blood pressure and plasma levels of aldosterone. Conclusion：Elevated serum PTH level is an important character in PA patients. Plasma levels of renin activity，serum levels of K+ and Ca2+ are main factors influencing the serum PTH level in PA patients. Elevated serum PTH level might relate with increased cardiovascular risk in PA patients.