Objective：To study the clinical value of real time-three dimensional echocardiography（RT-3DE） in evaluating the systolic function of the right ventricle. Methods：The right ventricular end diastolic volume（RVEDV），right ventricular end systolic volume（RVESV），right ventricular stroke volume（RVSV） and right ventricular ejection fraction（RVEF） were measured by RT-3DE and tri－cuspid regurgitation pressure gradient（TRPG） and systolic pulmonary artery pressure（SPAP） were measured by Doppler in 80 cases of acute pulmonary embolism. Eighty normal persons were taken as controls. Results：The values of RVEDV，TRPG and SPAP were increased but the values of RVSV and RVEF were decreased in the acute pulmonary embolism group compared with those in the nor－mal control group（P<0.05）. Conclusions：RT-3DE can reflect the changes of right ventricular systolic function objectively in patients with acute pulmonary embolism，which is helpful for the early diagnosis.