Objective To evaluate the characteristics of right ventricular flow field and EL in secundum ASD by VFM, and provide a reference basis for quantitative assessment of right ventricular structure and function in ASD. Methods 97 patients with ASD were divided into 30 patients with non PAH group（＜=30mmHg），25 patients with mild PAH（30-50mmHg），22 patients with moderate PAH（50-70mmHg） and 20 patients with severe PAH（＞70mmHg）. 29 healthy volunteers served as control group. Right ventricular vortex parameters and EL were measured by VFM，and the related evolution laws were analyzed and summarized. Results Streamline of the control group, the non PAH group and the mild PAH group all showed that there were more vortices near the tricuspid valve orifice in P1 and P2. In moderate PAH group and severe PAH group, there were different size, direction and number of vortices in right ventricle at different time phases of cardiac cycle; There was no significant difference in vortex area, circulation, vortex quantity and EL between the control group and the non PAH group at each time phase(P>0.05）, while they increased with the increase of PAH pressure in the mild，moderate and severe PAH group (P<0.05), and EL peak appeared in P1; EL was positively correlated with Tei index, E and E/e respectively (r=0.768, 0.941, 0.937, P<0.05) and negatively correlated with TAPSE, RVFAC and e(r=-0.864, -0.734, -0.817, P<0.05). Conclusion VFM imaging technology can display the characteristics of flow field and EL of right ventricular blood flow in ASD. It can provide a powerful basis for quantitative evaluation of right ventricular hemodynamics, PAH pressure and analysis of right ventricular EL application in ASD.