In order to treat the problem that left ventricle is hard to segment in two dimensional transesophageal echocardiography because of the speckle noise,a multi scale active shape model based on centripetal Catmull Rom spline was proposed.In the upper pyramid levels,2D profiles were extracted for each landmark and Mahalanobis distance was used searching new position for each landmark. In the bottom level,fast Log Gabor feature was extracted and trained using Gentle AdaBoost.The point with highest confidence level was the new position for each landmark in the fitting process.Experiments proved that this method is more accurate than traditional Active Shape Model and the segmentation result is interactive and easy to edit.