Abstract: Objective To investigate the relationship between exercise blood pressure during cardiopulmonary exercise testing（CPET） and left ventricular posterior wall end-diastolic thickness（LVPWD） in patients with primary aldosteronism（PA）, and to compare the incidence of exercise-induced hypertension（EIH） between the patients with PA and those with essential hypertension（EH）. Methods Sixty-six patients with PA and 82 patients with EH from Fuwai Hostipal Chinese Academy of Medical Sciences, Shenzhen between May 2017 and May 2022 were consecutively recruited. EIH was diagnosed using Framingham Heart Study criteria, i.e, exercise systolic blood pressure ≥210 mmHg（male）, ≥190 mmHg（female） and/or exercise diastolic blood pressure ≥110 mmHg. Main parameters in CPET including exercise blood pressure during each period of exercise, peak oxygen uptake（VO₂peak） were obtained. LVPWD was obtained by echocardiograph. The incidence of EIH, and the proportion of LVPWD thickening were compared between the two groups. Pearson/Spearman correlation analysis was used to determine the correlations of VO₂peak with sitting aldosterone to renin ratio（ARR）, serum potassium, and sitting aldosterone with LVPWD, exercise blood pressure with LVPWD. Multiple linear regression was used to analyze the relationship between exercise blood pressure and LVPWD. Results There were no differences between the two groups in the levels of 24 hour-blood pressure, daytime blood pressure, nighttime blood pressure of ambulatory blood pressure monitoring and peak blood pressure during exercise. The PA group had a lower level of VO₂peak than that of EH group （22.20±6.96） vs（25.55±7.20） mL/（min·kg）, t=-2.800, P=0.006. The LVPWD in patients with PA male: 11.00（10.00-11.75） vs 10.00（9.00-11.00） mm, Z=-1.973, P=0.049; female: 10.00（8.50-11.00） vs 9.00（8.00-10.00） mm, Z=-2.018, P=0.044, the incidence of EIH 53.0%（35/66） vs 36.6%（30/82）,χ~2=4.015, P=0.045, and the proportion of LVPWD thickening 30.3%（20/66） vs 12.2%（10/82）, χ~2=7.419, P=0.006 were higher than those in EH group. Spearman correlation analysis showed that VO₂peak was negatively correlated with sitting ARR（r_s=-0.210,P＜0.013）, aldosterone level in sitting position was positively correlated with the LVPWD（r_s=0.221, P=0.009）, peak systolic blood pressure and blood pressure at 1 min during the recovery period were positively correlated with LVPWD（r_s=0.188, P=0.027; r_s=0.217, P=0.009）. Multiple linear regression analysis showed that blood pressure at 1 min during the recovery period and aldosterone level in sitting position were independently correlated with LVPWD in the total sample. Conclusion PA patients are more likely to suffer from EIH than EH patients, and blood pressure at 1 min during the recovery period and aldosterone level in sitting position are independently correlated with LVPWD in the total sample.