The expertise and experience are required for an examiner to diagnose using echocardiogram. To evaluate the synchronicity of motion in the heart, the tissue Doppler imaging (TDI) technique is popular but it has anisotropy in motion detection. Therefore, we have developed software to recognize the synchronous motion of heart by calculating intersection points between the instantaneous velocities of ventricular wall flow from successive echocardiograms. In addition, we defined intersection index to evaluate synchronous motion of heart by dividing echogram into small regions to calculate distribution of intersection points. Finally we introduced gravity point of the distribution and calculated its trajectory through a heart-beat. As the result, fluctuation of the gravity point in heart disease patients was clearly observed where the trajectory of the gravity point was stable in normal subjects.