3D Quantitative measurement of left ventricle (LV) motion on patients with acute myocardial infarction has been recognized as essential for effective LV function diagnosis. This paper presents a method to quantify 3D LV motion obtained from conventional CINE MRI using image analysis based on mathematical modeling. Level set method is employed for segmentation, and a 3D LV geometry was reconstructed by co-registering different views of MRI images. A mathematical model of LV geometry was then constructed to quantitatively describe the LV wall inward motion. The results using real data show that the method is able to quantify the LV inward motion, and can clearly represent the changed motion pattern with the follow-up data. Furthermore, the LV motion analysis for 8 patients with acute myocardial infarction (MI) show that high inward motion occurs mainly in the basal region of LV while a negative relation is found between LV ejection fraction (EF) improvement after acute MI and solely basal region inward motion, which could be helpful for diagnosis and LV EF recovery prediction.