Abstract: Heart failure afflicts nearly five million people in the United States every year. Research ranging from basic cardiovascular cell biology to national-scale clinical investigation is funded to understand the mechanisms underlying cardiac dysfunction. However, the heart, the most important role as mechanical pump in the body, is rarely discussed from the perspective of mechanical elasticity and force distribution. The objective of this research is to establish a methodology to systematically analyze human cardiac function. For future clinical applications and an accurate understanding of the cardiac mechanics in a living person, a noninvasive derivation method based on medical imaging techniques was developed. Moreover, to take into account variations in myocardial contractility between individuals, equations to derive myocardial material properties in vivo were also formulated. A general biventricular model to describe force distributions in different cardiac phases was constructed using existing medical imaging data. Equations for local wall stress were solved by combining the nonlinear finite element calculation with myocardial forces which were calculated based on ventricular pressure and torsion during systolic contraction. Then the methodology was extended, and two individual healthy human heart models were constructed based on real ventricular geometry and physiological parameters. Large elastic deformation theory was applied to derive myocardial material properties for each subject. The three-dimensional ventricular wall stress throughout the cardiac cycle was obtained. By comparing the distinct endocardial wall stress between subjects, several interesting findings about the wall stress distribution were revealed.