A method and an apparatus for diagnosing cardiac diseases based on a cardiac motion modeling are provided. The method may include applying physical characteristics of a cardiac motion to a 3D heart shape model, deriving a boundary condition by fusing the 3D heart shape model to which the physical characteristics are applied and a plurality of cardiac ultrasound images according to a temporal change, obtained to acquire a dynamic image, and diagnosing the cardiac diseases using a result of modeling that models the cardiac motion of the user using the boundary condition.
