Abstract: We propose a collaborative web interior design system that assists multi-users in real time house editing and furniture arrangement. Our system incorporates the transparent adaptation layer, which is an important network protocol, to achieve the online multiplayer real-time collaborative interoperability. Instead of adapting the basic linear stack data structure provided by ActionScript, we optimize the tree-based data structure which is compatible with the transparent adaptation. Our results demonstrate that this system has the capability of supporting collaborative design with improved user experience and visual effects, real-time responsiveness, fast synchronization, and high stability.