Objective:To study the paradoxical septal movement after aortic valve replacement by two-dimensional echocardiography. Methods:58 patients with aortic valve stenosis and 16 cases of patients with aortic valve incomplete closure were enrolled in this study. Using two-dimensional echocardiography to measure left ventricular ejection fraction, left ventricular stroke volume, per minute output, paradoxical septal motion, ventricular septal thickening rate in preoperative and postoperative 7 days. Results:The left ventricular ejection fraction was reduced in the patients with aortic valve stenosis and aortic valve incomplete closure, the difference was not statistically significant.The left ventricular stroke volume and per minute output increased, and the difference was statistically significant. The range of ventricular septal motion was decreased, and the difference was statistically significant. There was no significant difference in interventricular septal thickening rate. Conclusions: Two - dimensional echocardiography can be used to evaluate paradoxical septal motion after aortic valve replacement.The effect of paradoxical septal motion on the overall contractile function of left ventricle.