The purpose of this study was to provide the reference information for current and potential users of apparel 3D CAD system by studying the functional characteristics of apparel 3D CAD study. The apparel 3D CAD system of Optitex, V-Stitcher and DC-Suite was selected for technical compara tive study.The results were at follows: 1. Three systems are similar in basic 3D system configuration and working flow. 2. In configuring a module, Optitex and V-Stitcher separate a 2D pattern and a 3D simulation, whereas DC-Suite configures a 2D pattern and a 3D simulation in one system. 3. In Optitex, a 3D Runway system performs 3D simulation works linked with its own 2D pattern - making software, Optitex PDS, after the 2D pattern is made. 4. In case of V-Stitcher, 2D pattern making is done linked with Gerber Pattern CAD and a 3D simulation proceeds. 5. DC-Suite was developed based on 3D simulation technologies, different from other systems. It includes its own 2D pattern-making technologies.