The traditional algorithm of voxels growth is improved to ultimately achieve the purpose of extracting the local blood vessels of the heart. The initial voxels seed spots are delineated on the local blood vessels of interest within the three-dimensional model of the heart. The initial voxels set adds new voxels, which are similar to the initial voxels set in terms of their gray-scale histogram. Newly added voxels as new seed spots continue to look for similar voxels according to growth rules. In order to prevent leakage problems during voxel growth, we sets the termination rule to limit the boundaries of voxels growth, and discover all the voxels included in the blood vessels. The improvement of growth rules and termination conditions of the voxels growth algorithm, to a certain extent, solves certain problems of the traditional voxels growth algorithm such as poor interaction and not real-time running. The algorithm has the advantages of high accuracy and good robustness, hence it is proved to be an effective imaging aid tool for the clinical treatment of cardiovascular diseases.