Objective To evaluate cardiac function and hemodynamics in patients with minimal-invasive surgical device closure of secundum atrial septal defects by transesophageal echocardiography, and to discuss the value of transesophageal echocardiography. Methods Echocardiography tests were performed in fifty patients with secundum atrial septal defects undergone minimal-invasive surgical device closure. The values of certain parameters for cardiac function and hemodynamics were measured and analyzed preoperatively and postoperatively. Results After operation, the size of both right and left ventricle and atrium decreased(P<0.05), the right ventricular end diastolic volume (RVEDV), right ventricular stroke volume (RVSV), right ventricular cardiac output(RVCO) decreased(P<0.05), the left ventricular end diastolic volume(LVEDV), left ventricular stroke volume (LVSV), left ventricular cardiac output(LVCO) increased(P<0.05), while the right ventricular end systolic volume(RVESV), left ventricular end systolic volume (LVESV), and the ejection fraction(EF) of both right and left ventricle changed not much. The peak velocity, mean velocity and velocity time integral of pulmonary valve, the peak velocity of E wave in tricuspid valve, the peak velocity of tricuspid regurgitation and the pulmonary artery systolic pressure decreased(P<0.05), while the peak velocity of E wave in mital valve increased(P<0.05). Conclusions Transesophageal echocardiography could be used as a tool in the evaluation of cardiac function and hemodynamics in patients with minimal-invasive surgical device closure of ecundum atrial septal defects.