Abstract: Isosurfaces are successfully used in representing the surfaces of organs and tissues from volume data. It is important to rapidly generate high- quality rendered image of isosurfaces. Unlike other isosurface rendering algorithms, the method proposed in this paper does not need to construct triangular mesh to approximate the isosurfaces and then render the set of triangular polygons. It displays the isosurfaces directly, so triangulation process is avoided and accuracy is improved,and manifests are eliminated.