Objective To assess the value of right ventricular (RV) structural mass parameters measured by cardiac magnetic resonance (CMR) in evaluating early impairment of RV function in pulmonary hypertension (PH) patients. Methods Fifty PH patients diagnosed by right heart catheterization in Tianjin Medical University General Hospital from Jan. 2015 to Jan. 2019 were retrospectively enrolled, including 17 patients in the preserved right ventricular ejection fraction (RVEF) group (RVEF ≥ 45%) and 33 patients in the reduced RVEF group (RVEF<45%); in addition, 25 healthy volunteers who underwent CMR in Tianjin Medical University General Hospital from Feb. 2014 to Jun. 2016 were included as healthy control group. The RV structural mass parameters such as right ventricular myocardial mass index (RVMMI), right ventricular trabecular and papillary muscle mass index (RVTPMMI), and right ventricular septomarginal trabecula mass index (RVSMTMI) were obtained by manually sketching on CMR cine images and calibrated by body surface area. Correlation analysis was used to analyze the relationship between RV structural mass parameters and CMR routine cardiac functional parameters and right heart catheterization parameters. The statistically significant parameters between the preserved RVEF group and reduced RVEF group and between the preserved RVEF group and healthy control group were analyzed using the receiver operating characteristic (ROC) curves, and the diagnostic value of these parameters in RV dysfunction or impairment in PH patients was evaluated. Results The time used for measurement of RVMMI, RVTPMMI, and RVSMTMI was 15 (14, 18), 20 (17, 22), and 2 (2, 3) min, respectively. RVMMI, RVTPMMI and RVSMTMI were positively correlated with mean right atrial pressure (mRAP), mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR) and right ventricular end-diastolic volume index (RVEDVI), but negatively correlated with oxygen saturation in mixed venous blood (SvO₂) and RVEF (all P<0.01). RVEDVI, right ventricular end-systolic volume index (RVESVI), RVEF, RVMMI, RVTPMMI and RVSMTMI in the reduced RVEF group were significantly higher than those in the preserved RVEF group (P<0.05); RVMMI, RVTPMMI and RVSMTMI in the preserved RVEF group were significantly higher than those in the healthy control group (all P<0.05). ROC curve analysis showed that RVMMI, RVTPMMI and RVSMTMI had good diagnostic performance for RV dysfunction and early RV impairment in PH patients (area under curve values were 0.864 and 0.894, 0.829 and 0.864, 0.842 and 0.953, respectively). Conclusion RV structural mass parameters (RVMMI, RVTPMMI and RVSMTMI) measured by CMR can reflect the early morphological changes of RV structures in PH patients, and have good diagnostic value for the early impairment of RV function in PH patients. Additionally, RVSMTMI, as a simple and intuitive index, has the potential for clinical application.