A　multi-material　segmentation　framework　which　is　able　to　separate　a　given　3D　image　into　more　than　two　segments　is　discussed.　First,　the　original　volume　image　was　segmented　by　3D　thresholding　algorithm.　Different　parts　and　materials　can　be　got　by　setting　the　appropriate　thresholds.　Then　the　segmented　parts　were　filled　into　a　blank　3D　image　one　after　another,　and　the　multi-material　segmented　image　was　achieved.　Finally,　the　result　was　visualized　with　volume　rendering　method.　This　framework　was　developed　based　on　the　VTK　and　ITK　libraries.　An　example　of　head　in　CT　series　images　segmented　by　this　approach　is　presented.