Abstract: A method is proposed to calculate the strain and stress of human left ventricle (LV) based on four-dimensional medical images.It promises to correspond the space information with the field of displacement to obtain better results than traditional finite element methods in which the displacement within each element is discontinuous and estimated by linear interpolation.Firstly, a B-spline model of LV surface is built based on boundary data extracted from the cardiac images in a sequence of time phases.Secondly, the displacement of tracked points is interpolated to establish a motion field with the parameters of corresponding points in the B-spline model.Thirdly, the relationship is determined by mapping the spatial B-spline models to the displacement fields.Finally, the strain and stress are calculated with the derivative of displacement fields.Experiments show satisfactory results.