This paper discusses the reason of triangle metamorphosis in Marching Cube Algorithm.According to there as on wegivea method to protect the metamorphosis.This paper also diseusses a new data structure-Sliee-objeet-based(SOB) strueture，which advances the algorithm.The experiments show that SOB method takes the same rendering time when there is only a objeet in dataset.But if there is more than one objeet，octree alogrithm takes few times rendering time than SOB algorithm，so if the datasetdoes not contain so many voxels，it is meaningful that less iso-surface rendering time is taken by the lost of the approximate memory spaee.That is to say SOB algorithm excel so ther methods when the dataset contains more than one object，e.g.octree algorithm an drun-length encoding algorithm，in the executing efficiency.When the dataset contains more than one object，octree algorithm only use one octree data strueture for all objects，so when we want to render one or several of the objects，this algorithm need to create the octree strueture ain. SOB algorithm is not so，it creates the SOB structure for each of the objects from the beginning of rendering，so we can render any one of objects selectively according to user's interest，so SOB algorithm 15 adapt to interactive rendering.