Echocardiography is the most convenient means for both physicians and patients for heart disease diagnosis. The 3D+1D echocardiogram provides important information for evaluation of the 3D heart function such as the ejection fraction or the wall motion. The most basic task to evaluate such functions of a heart is to segment the left ventricles and reconstruct the 3D geometric model of left ventricle from a set of echocardiographic images. Since there are many images involved, the method should not need too many user assists. In this work, we design a method for reconstructing the left ventricles with very few user assists.